I flashed CyanogenMod 10.0 stable on my Vibrant last night and it's working really well. The only thing is that if I reboot into recovery from the long-press Power menu, the device reboots normally instead of going into recovery. If I use the Power+Volume Keys combo to get into recovery it works, but choosing the "reboot system now" option from there does not — it goes into an "unknown upload mode" like when I reboot with Power+Volume Up.
Holding the Power button to reboot works, of course.
Is there any way to fix this? I'm using the ClockworkMOD Recovery that was installed automatically when I flashed CM, v188.8.131.52. ROM Manager tells me that there is no recovery available for my device so this is obviously something custom for the CM Vibrant build.