Gears tried to update itself automatically, but stopped with an error telling, it is not compatible with my system, all the time. My workaround: uninstall, and install it manually failed. I was not able to install it again.
The file install.rdf within the actual .xpi file shows:
<!-- Prevent this XPI from being installed on the wrong platform. -->
The problem is, google packed the 64-bit version instead the 32-bit version, which will not run on a 32-bit System.
To get gears running again I had to install an older, correct packaged version. Gears version 0.5.32 can be downloaded here: