Used 1.0.3 extensively, never saw a problem. But after upgrade to 1.2.1 the front end of my site crashes quite regularly (js errors, white screen, etc). Turned off the bot and all is well again.
It seems to conflict with the JWvideo player that is used in most video systems/modules out there. It also seems to conflict with some types of flash or flashy ads.
Firefox is fine. Verified the IE7 crash on half a dozen different machines. While clicking around
www.nonumber.nl I have observed the same type of crash here as well (recently, not on every page, intermittent).
I am using J1.5.10, PHP 5.2.6,