InfoPath Dev

I have a 2007 InfoPath form published as a content type and browser enabled.  The submit button saves the form back to the form library it was opened from.  There is a unique naming convention to the user saving the file along with date and time.  My issue is that there are times when a user can open the form, fill it out, and submit it but the form will not get saved.  There are no errors that pop up on the screen or in the event viewer.  The user will go in 3 or 4 times and submit the information before it will save.  When this happens, it will happen to a group of 5 or 6 users around the same time.  Has anyone else seen anything like this before?

Did you ever figure this issue out?  It doesn't sound like an InfoPath issue, it sounds more like a server issue - server timeout.  I see you did check the event log - was that for the IIS box only, or did you also take a look in the SQL Server event log as well to see if antything is popping up there that could explain this.