I created a workaround for my gears problem by manually changing the version number within the .xpi file from 0.5.32 to 0.5.33. It seems to be working. Since yesterday there was no attempt for an automatic update.
You can download the patched file here: gears-linux-opt-0.5.32-patched.xpi
There is a more recent version than 0.5.33 available. The patched file contains now the version number 0.5.36