Box 1 - ECS mobo, Celeron 430 1.8Ghz, 2Gb ram, Hitachi deathstar 1000, WHS SP 2. Built it myself with left-overs on the cheap to try WHS.
Honestly, that's never a good idea (especially on a device where you would, in theory anyway, store your most valuable documents, such as irreplaceable photos, personal tax documents, etc.). I don't know how many times people have tried to cheapen the cost of their server by using old, worn-out parts and had issues (even I did that during the WHS beta). When WHS went RTM, I ended up buying all new parts and everything has been working fine for 2+ years.
Constant indexing and corrupted file problems on my 250Gb of music. I also use it to stream to my Xbox. Connects fine to everything but Win 7.
Box 2 - Intel Q6600, Asus mobo, 4 Gb ram, 3x500Gb RAID 0, Win 7 Home Premium x64 (released). All worked fine with Vista then I migrated to Win 7 RTM.
At this point you really should do a Server Reinstallation (just to wipe the slate clean), and install only drivers that are necessary in order for WHS to function (NIC, storage, etc.; not video for example) and only the critical updates for WHS by using the Update Now button in the Console.