[rex]

i think the bot.cfg is exec at the start of every map.(not 100% sure is this right Stefan?)
in which case you would be try to add bots on top of bots i think.
try taking the "realbot add" lines out of your bot.cfg file and making a file in your cstrike folder (eg: half-life\cstrike)
call it what ever your want and make it a cfg file eg: addbots.cfg
now put your "realbot add" lines in here when you load your first map just exec your new file in the console eg: exec addbots.cfg. this will add your 10 bots to the game. Now you shouldn't have to exec your .cfg file again as the bots should still be there where a new map loads.
couple of the things you can try are.
mp_autoteambalance 0
to turn Auto-Balancing team off
and
remove
realbot max 10

if thats don't work put it back, and add
realbot min 10

hope this helps