New to Painter but so far very cool.

As soon as I try to open up anything semi big (600megs or so) I get a message saying "not enough disc space to open another file"

No files currently open and my computer should handle it (I think). Using a new macbook pro 2.33Ghz, 3Gb ram, 111Gb hard drive with 54Gb free space. Also using a wacom cintique 21 tablet. Fresh boot up too so no other programs open.

Is this the upper limit to the program? Using Painter X educational. Was told by a Corel rep the program is 100% same as non-educational version.

any ideas????