Problems with Outlook at .ost file.

I have a user who's outlook is set up and connected to exchange, he is using .ost files, offline folders.
He's been getting errors telling him "Data file not closed properly" and then outlook checks the file, which can take a long time. To remedy this I turned off cached mode, closed outlook, then opened outlook again and turned cached mode back on and outlook was fine for him for a couple weeks, but now he is getting this problem again.

Along with this he is also getting this error:  Cannot start microsoft outlook. Unable to open the outlook window. Outlook cannot open the data file C:/documents and settings\username.ourdomain\local\settings\application data/microsoft/outlook0.ost until it has been checked for errors.

Here is my original question on the matter which I thought I had figured out but apparently not which should also outline all the things I have tried so far to fix this issue.

https://www.experts-exchange.com/questions/23314815/Getting-error-Data-file-not-closed-properly-in-Outlook-2003.html


I am really not sure what I should do next, I will have the users laptop today so I wanted to go through and try to fix this problem for good.