Some info about OS (W32 / Linux), Server (listenserver / dedicated) and bot version + a list of all mods you're running would make it easier for other RealBot guys to help you...
if you have AMX running, then this might be helpful (other bots also had problems; it seemed to be AMX-related):
http://forums.bots-united.com/showthread.php?t=1534
If not, I fear I can't help you much since I don't have RealBot. Did you try the usual Steam tricks like deleting clientregistry.blob, custom.hpk and check for your mp.dll? Just some suggestions; if you aren't too sure, better rename instead of delete - not to make matters worse than they are.
Btw, I can only recommend installing CS 1.5 as a waypointing installation and use 1.6 for playing only. 1.5 is more robust and cannot be affected by auto-updates...