How do I remove my photos from photoshop.com without deleting them from the sync'd album on my compu

I'm trying to remove files from photoshop.com to get back under my 2GB limit, but when I deleted files from within photoshop.com, they were also deleted from the sync'd album on my computer, and I had to rebuild an album with 500 photos in it.  I also don't want to end up accidently deleting them from my catalog either.  I'm using PSE 10 on a Windows 7 computer with 12GB RAM.  Any thoughts?  Thanks