Strange Behavior with EXCEL 2013

Hello everyone. I'm on a shared network, working with files on a mapped drive, and excel 2013 seems to be causing some strange things to happen. I don't know what caused it, or what has changed, but it used to be working just fine.

The program will frequently crash upon opening a shared worksheet. It doesn't matter which worksheet it is, and it doesn't seem to have any pattern. Another thing I've noticed is that instead of saying "Openpurchaseorders.xls" is reserved by Jacob, the name of the file is replaced by strange chinese looking characters or webdings and strange symbols. Is there a corrupt file somewhere that's causing these issues? Any tips?

Regards

Screenshot 2014-01-21 19.21.01.png

Here's an example of what happens. Note that I can type in the password or click read only and the correct file opens, I just figured the problems may be correlated since they started happening at the same time.

It seems like the problem lies with old xls files... the problem is absent from xlsx files. It's also only been a problem since this computer was switched to Active Directory. The XLS files worked fine until then. I also happen to be having a bunch of network related issues recently, so I'm starting to think that Active Directory is the cause of all of these glitches.