Commented Issue: Exception of type 'System.OutOfMemoryException' was thrown. [8056]

I am getting this when I do " workbook.SaveAs(filename) ". Is there anyway I can fix this?
 
Thanks
Comments: I don't get it, SaveAs is the last thing you do, so if you do the SaveAs and then exit the function then the wb/ws references will be invalid and thus garbage collected. Even if they're not garbage collected, the process is done. Can you clarify?