Windows 7 - Homegroup

I'm sorry to start a new thread about this, but I've done some searching, and I just can't seem to find an answer. Here's my history (press pause and get a coffee now):

I have a home built DualCore Intel Core 2 Duo E7200 chip sitting on an Asus P5K board connecting to my network via a D-Link DWA RangeBooster N USB Adapter. I'm connecting up to a 2Wire modem/gateway provided by my IP.

The homegroup has previously worked for me when I was running Win 7 RC Build 7100, connecting to a laptop with Win 7 Home Premium on the same wireless network. A few days ago I "upgraded" my PC to Win 7 Home Premium, and of course re-established connection to the same network. I created a new homegroup and tried to connect from the laptop. I could see the homegroup, even go in and see what it is sharing, but when I clicked on any folder it would say that it couldn't connect to the //PC-Computer.

So I left the homegroup on both PC and laptop, restarted, and proceeded to re-make the homegroup on the PC. I then joined from the laptop with no problem. I can still see the PC sharing the libraries, but now when I click on the folder to open it, it just sits there and does nothing, not even an error message.

I have made sure my IPv6 is enabled, and have gone through the Ultimate Troubleshooting Guide for Windows 7 HomeGroup Connection Issues.

Would anyone have any ideas?

** I just shared a folder directly, instead of through a library. I still get the message "Windows cannot access \\MG-PC\foldername"

So I tried to access my computer via the Network instead of Homegroup, and I get the same message "Windows Cannot access \\MG-PC". The details are error code 0x80070035 "the network path was not found". If its not found why can I see it in the listing?