I was searching for a doc using finder( I just did a search for "all files created today") and all my Address Book files( .abcdp) were displayed as have being created/modified simultaneously a few hours before. I had not opened the address book app. for a number of days so I got a little worried at what had caused this so I ran a virus scan using protectmac and it came up clean. I also checked if any other files/apps etc had been created that day and there was nothing obvious. All I did that day was download some docs(sheet music) on a file sharing site ( which I have done many times before with no problem) and watch some stuff on youtube/blinkx/metacafe.

All the files in the address book only contained tel. no's and seem unaffected.
So does anyone have any ideas what caused this?