The Ghost bug

[skinny killer]

I'm having a prob in one of my maps that will allow the player to walk through solid objects. it is kinda weird. everything goes fine until about 20 seconds into the map. then the player has the ability to walk through walls.

then 10 seconds later it all goes back to normal?!?!?!?!?!

this has happened before and my good buddy Dave said it was a BOT error. so he deleted one bot at a time until it fixed the prob. but I've tried deleting all of the bots and it fixed it but when I started to replace the bots I deleted and add new ones it started doing it again.

does any one know what kind of BOT error causes this bug? I need to find a way to avoid it. replacing bots is NOT fun.

Thanks a million!
Killer