Mint 12: Connections to Windows 7 machine drop randomly

[Objekt]

My LAN setup is ordinary, with a gigabit router (Netgear WNR3500v2) supporting three PCs (two wired, one wireless) and a network printer (wired), connecting to a cable modem for Internet access. One of the two wired PCs runs Windows 7, and is primarily used as a file server. It is on at all times.

While I'm able to see shares on my Linux Mint 12 machine from my Windows 7 machine and vice-versa, the Samba connections to stuff on the Windows machine (file path something like smb://...) drop randomly.

I mostly use the Mint 12 machine to watch stuff stored on the Windows 7 machine. This dropping of connections is therefore quite annoying. I usually notice it while watching a movie, because the player app (VLC Media Player) will simply freeze.

Then I go to Nautilus, and find that the Windows machine's shares - which I have bookmarked in Nautilus - cannot be accessed.

Sometimes, the video will freeze up, but I can get back where I was by re-starting the player and re-loading the media in question. This could be a VLC Media Player issue, but I'm not sure.

When the connections to the Windows machine have become inaccessible, either restarting the Mint machine, or logging out of/back into Mint, will fix the problem. At least, until the next time it happens, which may be hours or days later.

FWIW, the Windows 7 machine is set to never enter sleep/hibernate/etc. although the display does turn off after a period of inactivity.

I'll post samba.conf and whatever other config files are relevant later, when I'm on the Mint machine. In the meantime, any ideas?