Gina's advice, as usual, is dead on! Having multiple users sharing a single Front End, on a network drive, is a sure way to repeated episodes of corruption, speed and timing problems, and all manner of strange, odd and curious behavior!
Being in forced retirement, I spend 8-10 hours a day here and on other Access forums/newsgroups, and over the past twelve years have seen literally dozens and dozens of reports of split databases, using links to a single Front End, causing these kinds of problems, as well as massive data loss! The really insidious thing is that this kind of setup can work for extended periods of time before the troubles begin! But once it does, they become chronic, which is to say they occur over and over and over again! So, as Gia said, give each user their own copy of the Front End and see what happens.
The OLE Server error usually, but not always, is associated with the opening a Form, and can be caused by all kinds of things, but to the best of my knowledge, it is very seldom, if ever, actually connected with communicating with a OLE server or ActiveX Control!
The most common cause, going by what I've seen online for the past twelve years, has to do with using a non-English language with Access, and the need to set the language for non-unicode programs to that foreign language. Here's a link explaining this:
You receive an error message when you start Visual Basic for Applications code in an Access database
Linq ;0)>
The problem with making anything foolproof...is that fools are so darn ingenious!
All posts/responses based on Access 2003/2007