First thing to do is to unplug the cable box, wait a couple of minutes and plug it back in. The problem isn't necessarily in the remote.

Use the 990 command to blink back the setup code on cable.  I expect it will be 01376.  Write it down so you can revert to it later.  Other possibilites are 01982 (some new Motorola boxes) and 01877 (Scientific Atlanta).  YOu want 01376 or possibly 01982.  To reassign the cable setup code, first do a 982 command to unlock the setup code.

If you're still having trouble, make sure that the LEDS flash when you press a button, and use a cell phone camera viewfinder to look at the output of the remote.  You shuld be able to see flashes when pressing a button.