Sounds normal.

As many folk have moved to many megapixel images you see the document sizes leap in size. BUT THAT'S NOT YOUR ISSUE.

It appears you are seeing a limitation in this app. To conserve disk space I suggest you save that in a compressed folder. XP supports that so here's a link.

http://www.tomshardware.com/forum/47003-32-enabling-ntfs-file-folder-compression

Bob