Alright I will explain the issue as detailed as possible.
We currently have 9 windows 7 machines in our network of 400 computers "the rest are XP". All but 1 experience this problem. Periodically throughout the week the boxes will lose their connection to certain shares. It's not always the same shares. And every time you can still access most other shares on the server. So it is not a complete loss of all shares. It will be just 1-3 shares at a time. It is not on all Win 7 computers at the same time either. It is not after leaving the computers idle for a long time either. I have had it happen to me in the middle of moving all files from one share to another. Right in the middle of copying over 17GB worth of data it just randomly disappeared. Thank goodness for backups! But usually rebooting the Win 7 computers will resolve the connection. But some times it will take up to 5 reboots to be able to connect to the share. Which can be very frustrating to the employees who are trying to work. Also there are times it is 2 weeks between having this happen.
It is very strange in the sense that the share basically just disappears to the Win 7 computers. It doesn't throw an access denied error, it simply states it does not exist. Even trying to go to the share by "\\IP-Address\share-name", results in location does not exist. You can even navigate to the server shares simply by going to "\\server name or IP address" and you will see all of the shares and can access them aside from the 1-3 that stopped working. They simply aren't there. Also it is not gone to all computers at once. If one computer can't see a share the Win 7 computer right next to it can.
Also I wanted to add that the number 1 share we are having issues with is our redirect share for "My Documents". Basically it seems that all of them will lose this connection at some point. Not sure if it is a problem with the redirect, or if it is just happening more on that share due to do it is the one most used. I am also unsure if it is an issue with Server 2003 or Win 7.
None of our Win XP computers have this issue. And yet 1 Win 7 machine has never had this issue. They are all the same brand PC from Lenovo. We use WSUS to control updates so they are all on the same updates. They all have SP1 installed. There is no AV on the server. All machines have the same AV. We use Trend Micro Enterprise.
Any help would be greatly appreciated!