The computer that has this problem for me is ATI. That said, I haven’t tried vorpX in months — I’ll check tomorrow (update all relevant software first — vorpX, ATI driver, Oculus SDK and firmware) and let you know if it still happens.
In the Source/SteamVR version of the problem, if I take off the headset and look carefully into its screen, I’ll see there are actually 3 pictures there; they’re positioned precisely right, so when I have the headset on, I see two (the middle one overlaps with the left for the left eye and the right for the right eye). I’s a little funny actually :-) I guess vorpX and SteamVR are both “stereoscoping” the image in turns
I’m having this problem with Portal 2, I believe it’s because I installed and tried SteamVR :-/ now I can play it on the Rift just fine if I turn off vorpX, but I want to try with vorpX so I get head tracking. Anyone has an idea how to turn off SteamVR? I find the option in the config for Half Life, but not for Portal 2.