I got this error above after updating to ubuntu 10.10 and trying to continue my adventure with mono + winforms. It p***ed me off a bit, because I couldn't find any solution to this on the net. The reason for the error was pretty silly - some UIAbridge classes implemented Table interface, which was recently modified, and, unfortunately the implementing classes weren't. I even found some typical //TODO: fix it comments in the code...
Here you can download the library UiaAtkBridge.dll.zip (compiled on x86, ubuntu) or the source code to compile on your own.
Hope this helps!
Regards!