you are right, you do not need realfix. But i believe CS 1.5 is too old for the new metamod. However, you seem to got it running so just make sure your realbot is set up for CS 1.5 as well!
* ah, just popped into my mind the metamod dll used at the filebase is also CS 1.5 compatible
Anyhow, make sure the realbot version is set okay! check the wiki help page for the correct command.