RAMSS Maximum File Size?

Is there a maximum file size limitation to RAM that's not published anywhere?  I've tried looking but can't seem to find anything definitive.  Twice, now, I've saved a large .rss file.  The file seemed to save fine, and then when I later went to open it up I get the warning below.  I definitely have plenty of space on my hard drive, and I'm working directly off my desktop, so I must believe it's a limitation of the program.

The first time this happened the file size was just shy of 5 GB.  This file is around 5.5 GB.  It's pretty frustrating to have to revert to a backup file for no apparent reason, when all I was trying to do is save some analysis results so I could come back to them later...