well...maybe there are two ways to solve this... I had similar problem. First make sure that you have a hard wire connected to your computer, not wireless..
Restart and at menu select where you can start BT in a safemode if possible. BT 5r3 has this ability, not sure about others... anyways...
Then you are brought to a screen that is blue.....and you have you use ur arrow keys.. scroll down to the one that asks "fix broken packages" it should automatically connect download and install any broken packages and solve most issues... IF this fails.... then....
Boot into BT. If you can, have a hard line for internet plugged in. (makes it faster and doesnt cause connection problems as wireless sometimes does)
Bring up terminal. ctrl+shift+T
make sure you are in root.
Note..... if you run the following commands, it will update your bactrack, to the most current version of backtrack.....
apt-get update && apt-get dist-upgrade
Note* You can try the first option and that should fix your issue.... and will enable you to keep everything as it is, it just repairs them.. but if you want to completely update and upgrade to BT5R3, then the above command will allow it to happen.. This will take about 20-30 minutes to complete...
email me and let me know how this works out, or if you have any more questions..... matthew3041230@gmail.com


