Hi there
I am runing kali-linux-1.0.6-i386(kernel 3.12) as a live boot from usb.(keep this in mind, i can't reboot)
I got an Alfa Awus036nhr v.2 with RTL8188RU chipset and was trying to deal with txpower option.
So as posted many times in here i just went for the backports way.

Code:
apt-get install build-essential linux-headers-$(uname -r) 

got the lstest stable release of backports (backports-3.15-rc1-1.tar.xz)
tar -xvf back*.xz

modified from backports/drivers/net/wireless/rtlwifi/regd.c  the line "REG_RULE(2412-10, 2462+10, 40, 0, 20, 0)" to "REG_RULE(2412-10, 2484+10, 40, 0, 33, 0)".

cd /root/backports*
make defconfig-wifi
make -j4
sudo make install
ok since here no errors were shown.

inserted the usb adapter and this were the kernel logs

Code:
root@kali:~/backports-3.15-rc1-1# tail -f /var/log/messages
May  9 16:27:39 localhost kernel: [ 1688.396911] rtlwifi: disagrees about version of symbol ieee80211_rate_control_register
May  9 16:27:39 localhost kernel: [ 1688.396913] rtlwifi: Unknown symbol ieee80211_rate_control_register (err -22)
May  9 16:27:39 localhost kernel: [ 1688.396948] rtlwifi: disagrees about version of symbol wiphy_rfkill_start_polling
May  9 16:27:39 localhost kernel: [ 1688.396951] rtlwifi: Unknown symbol wiphy_rfkill_start_polling (err -22)
May  9 16:27:39 localhost kernel: [ 1688.396966] rtlwifi: disagrees about version of symbol freq_reg_info
May  9 16:27:39 localhost kernel: [ 1688.396969] rtlwifi: Unknown symbol freq_reg_info (err -22)
May  9 16:27:39 localhost kernel: [ 1688.396981] rtlwifi: disagrees about version of symbol rate_control_send_low
May  9 16:27:39 localhost kernel: [ 1688.396983] rtlwifi: Unknown symbol rate_control_send_low (err -22)
May  9 16:27:39 localhost kernel: [ 1688.397011] rtlwifi: disagrees about version of symbol ieee80211_rx_irqsafe
May  9 16:27:39 localhost kernel: [ 1688.397014] rtlwifi: Unknown symbol ieee80211_rx_irqsafe (err -22)
the casrd is present in lsusb

Code:
root@kali:~# lsusb
...
Bus 002 Device 005: ID 0bda:817f Realtek Semiconductor Corp. RTL8188RU 802.11n WLAN Adapter
...
the rtlwifi or rtl8192cu modules wont appear under lsmod
Code:
root@kali:~# lsmod
Module                  Size  Used by
rtl8192c_common        60091  0 
compat                 12764  0 
fuse                   72994  3 
nfnetlink_log          17065  0 
nfnetlink              12853  1 nfnetlink_log
binfmt_misc            12733  1 
dm_crypt               22008  0 
dm_mod                 78673  1 dm_crypt
joydev                 16884  0 
arc4                   12487  2 
iwldvm                120645  0 
uvcvideo               69726  0 
videobuf2_vmalloc      12720  1 uvcvideo
videobuf2_memops       12471  1 videobuf2_vmalloc
videobuf2_core         34719  1 uvcvideo
mac80211              405587  1 iwldvm
videodev               90742  2 uvcvideo,videobuf2_core
i915                  601624  7 
media                  17840  2 uvcvideo,videodev
drm_kms_helper         35367  1 i915
snd_hda_codec_hdmi     35210  1 
drm                   198264  3 i915,drm_kms_helper
snd_hda_codec_realtek    40657  1 
intel_powerclamp       12882  0 
snd_hda_intel          34975  3 
i2c_algo_bit           12647  1 i915
i2c_core               23371  5 drm,i915,drm_kms_helper,i2c_algo_bit,videodev
coretemp               12734  0 
snd_hda_codec         130764  3 snd_hda_codec_realtek,snd_hda_codec_hdmi,snd_hda_intel
iTCO_wdt               12727  0 
snd_hwdep              12906  1 snd_hda_codec
snd_pcm                69436  3 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel
snd_page_alloc         12882  2 snd_pcm,snd_hda_intel
snd_timer              22002  1 snd_pcm
snd                    50767  13 snd_hda_codec_realtek,snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_pcm,snd_hda_codec,snd_hda_intel
kvm_intel             129032  0 
soundcore              12890  1 snd
iTCO_vendor_support    12585  1 iTCO_wdt
iwlwifi                78523  1 iwldvm
acpi_cpufreq           13019  1 
kvm                   321655  1 kvm_intel
psmouse                76538  0 
mei_me                 13230  0 
lpc_ich                16616  0 
mei                    44836  1 mei_me
asus_laptop            22286  0 
serio_raw              12737  0 
sparse_keymap          12680  1 asus_laptop
crc32c_intel           12659  0 
mfd_core               12537  1 lpc_ich
cfg80211              351819  3 iwlwifi,mac80211,iwldvm
video                  17506  1 i915
input_polldev          12802  1 asus_laptop
battery                12949  0 
intel_ips              17182  0 
evdev                  17172  9 
rfkill                 18414  3 cfg80211,asus_laptop
ac                     12588  0 
button                 12824  1 i915
processor              27662  1 acpi_cpufreq
squashfs               30755  1 
loop                   21962  3 
aufs                  162179  3915 
ntfs                  201786  0 
nls_utf8               12416  1 
nls_cp437              12417  1 
vfat                   17009  1 
fat                    52677  1 vfat
usb_storage            43325  1 
hid_generic            12369  0 
usbhid                 39684  0 
hid                    80998  2 hid_generic,usbhid
sg                     25628  0 
sd_mod                 43598  4 
sr_mod                 21563  0 
crc_t10dif             12399  1 sd_mod
cdrom                  34540  1 sr_mod
crct10dif_common       12340  1 crc_t10dif
ahci                   25000  1 
libahci                26693  1 ahci
ehci_pci               12432  0 
ehci_hcd               43677  1 ehci_pci
atl1c                  35834  0 
usbcore               137931  5 uvcvideo,usb_storage,ehci_hcd,ehci_pci,usbhid
usb_common             12408  1 usbcore
libata                153595  2 ahci,libahci
scsi_mod              151284  5 sg,usb_storage,libata,sd_mod,sr_mod
thermal                17268  0 
thermal_sys            22960  4 video,intel_powerclamp,thermal,processor
if i try to modprobe
Code:
root@kali:~/backports-3.15-rc1-1# modprobe rtl8192cu
ERROR: could not insert 'rtl8192cu': Invalid argument
So why an i getting those Unknown symbol ieee80211_... kernel errors?
Do you have any idea?
It's been three days i've been searching all around for a solution but i have made no progress at all.