I've got a pentax *istDL and every time I import raw photos into iPhoto I get the same problem.

If I try to zoom or do any basic editing EXCEPT crop I get what appears to be the photo superposed on top of iPhoto. I can move iPhoto around under the locked picture but I can't do anything with it. If I crop the photo first,even selecting ALL of the picture then I can usually work on it.

Any clues or solutions. This is on a G5 iMac with the latest version of iPhoto/iLife.