Win7 Explorer Hangs While Accessing Shared Homegroup Folders

I have three computers all running Windows 7 Ultimate x64, one of which functions partly as a media center (hosting music etc), the second and third being my office workstation and laptop respectively. The media center has a hard line to my cable modem (via Trendnet wireless-N router) while the latter two connect via wireless; the workstation via a wireless ethernet hub and the laptop via it's integrated wireless.

I currently have all of my media folders shared via homegroup on the media center.

My laptop (Lenovo Thinkpad W500) can access all of the shared folders. I have a wireless printer that all three computers (media center, workstation, and laptop) can connect (and print) to with no problems.

My office workstation, while I can "see" the shared libraries/folders on my media center, hangs (the explorer window appears to be perpetually loading) whenever I attempt to open any of the folders. Sometimes when this happens I can kill/restart explorer but ever so often explorer itself will be unable to restart and I will have to reboot the entire machine.

I have Windows Security Essentials running on both machines - all three are almost identical with respects to the installed software.

I have tried reconfiguring the homegroup multiple times, flushing the dns cache, even swapped out adapters to no avail.

Any advice would be much appreciated!