Before someone flames me, I did spend over an hour searching this particular issue
I'm running a GPS unlocked custom ROM I picked up here about six months ago. The phone runs fast, no problems, GPS locks in 10-15 seconds. No real issues other than tethering.
I don't have an "internet sharing" program to start, but I do have the "modem link" which seems to have the same functionality. I can run it, connect, then the PC tries to load a "generic serial" device (no drivers found). I've allowed wireless connection in active sync and I've looked for other options on the phone but I can't find any. Is the tethering option something that's been added in the last kitchen ROM or two? If so I might not have it. Is there an easy way to check? I keep reading about "internet sharing" options, but I don't see anything on the device (verbatum) that says that. Ideas? Thanks!