"An error was encountered while trying to open your file." - any ideas how to get around this error?

I'm trying to open a very large (160Mb) assembly file and am getting this error "An error was encountered while trying to open your file.  Contact Technical Support for a possible solution".  Other files open fine.  The last time I looked at this file was a week ago, and it was fine then.  I don't have any old backups, so I would really really really like to recover this version if at all possible.  Anyone have any suggestions?  I'm using Solidworks 2011 x64.

Thanks so much for your help.

Michael

SolidworksGeneral