explorer crash

hi i’m running xp sp3 - CIS (firewall and D+ proactive settings) I also have Kaspersky AV 2009 - and i noticed that explorer crashes when i highlight (just 1 click) some big files (avi files> 500 mbs) with long names . no problem with other files. I think tehre must be a problem with memory access cause its says “memory can’t be writen”…
same problem when i stop KAV or CIS…
any idea ? :THNK