Can't access Windows 7 shared folders from media box

Hi,

I'm using Windows 7 Home Premium 64bit and it's on a network with a Techgear MB902 PVR. I used to be able to watch movies in my W7 shared folders on my TV via the MB902 but after I bought a new PC and installed W7 I've had problems accessing the W7 shared folders.

When I connect to my PC it asks for a login and password, and none of my pc or network passwords work. Strangely enough, when I restart W7 the problem goes away and I can login successfully without a password, but then later the same day or the next day the login/password problem has returned.

I've trawled the internet looking for solutions, and tried all of the plausible looking ones, editing the registry, unsharing and then resharing. They all seem to work but then I realise that it's the reboot that works and not the fixes because the problem returns.

The MB902 has a hard drive and I can access the files on that from my PC with no issues it's just going the other way that I have problems.

Any suggestions would be greatly approciated.

Cheers

Follow up with some details:

The shared folder on my pc that I'm trying to access is the one that my bit torrent client saves completed downloads to.

When there are no changes to the folder, ie client is closed, or no recently downloaded files then I can connect to the folder no problems with no requests for login and password.

However if I've completed a BT download since last connecting to the folder, that's when the connection/login problems start.