cannot run some programs if antivirus enabled

Running XP64 & Avast 7. When antivirus enabled cannot run Corel graphics, can run some others. When antivirus disabled can run the graphics.

Note, this is a dual boot machine. It will run in safe-mode only in Win 7.

I don't know if this is related:
firefox on the C drive stopped running a week ago [after a scan]. The Win 7 version on the D drive ran both from XP and Win 7 until yesterday. Today it stopped.

I've tried a number of fixes suggested on the Avast and Mozilla forums.

 

Welcome to MajorGeeks. Someone should be able to help you shortly.

My thoughts on this, is you should be able to exclude directories in the antivirus program. Doing so is a risk, but if the AV is preventing you from running a program, then it is a must. We do this a lot at work.