I thought at first it might be something to do with JOCL which is why i sent you over here, but I traced through the code and see nothing obviously wrong. I also noticed some of my old code which used to work - or at least not fail at that point - was doing the same thing.
I'm using catalyst 11.9 drivers on linux, which appear to be buggy as hell but with my card I have no choice (it seems, i can't get of older packages for fedora anyway, and the 11.8 drivers wouldn't install on the ms-side of the dual-boot). Perhaps you can try a previous version though?
There's no mention of it on the AMD forums, but a lot of people seem to be avoiding the 11.9 drivers too.
I previously had nvidia hardware, and i can't remember the version i had my other box before i 'upgraded it' and stopped using it regularly as a workstation (that has an amd card, and i did some opencl on it, although i can't recall if i got to the opengl interop by then).
The only version i could get to work on fedora were from rpmfusion - the amd module builder is too broken and I didn't have the patience to trawl through rpm scripting errors and C++ build-errors-that-just-look-like-warnings-to-me to get it to work. But maybe you'll have better luck on ubuntu.
Incidentally they just released 11.10.
Seems to be two numbering schemes, 8.89.2 == 11.9, 8.86.x = 11.6, so 8.84 is probably a bit old.
Still, maybe it points to some other problem if other driver versions are affected.