I'm using a windows based stock screening software on a Mac PowerBook with Parallels for MAC with Windows XP. I often need to select multiple items on a page as I'm scanning through charts to move to another page. As I work I select these Items by holding down the control key and left click to highlight items. While I'm working the items un-highlight themselves. I have used this function many times before on a windows xp computer wothout any problems. Through further analysis I have found that when the windows desktop opens up and makes it's ring sound (or whatever that sound is when it starts), from that point on it appears that a 1 minute clock starts. For example the ring sound happens at 10 seconds past the minute. When I open my scanning software I can highlight items on the list wait and at 10 seconds past the minute they items in the list un-highlight. When I close the application and restart it and highlight an item at 10 seconds past the minute it un-highlights. If I restart the virtual machine and windows rings at say 25 seconds past the minute this is now the time at 1 minute intervals items will now un-highlight themselves. I have tried other windows applications in this environment and this does not occur Eg. Explorer or text editing. I don't think it is the scanning application I'm using as I can use it this way without errors on my windows desktop. I spoke with tech support for the application and there is nothing that can cause this on their end. Any suggestions would be great as this really slows things down as I work.