I have been waiting since Firefox 3.5 came out for Google to update Gears to be compatible. I had gears 0.5.21.0 installed and tried updating add-ons, which disabled gears, and going to the gear’s website, downloading and installing gears.
What I ended up doing was uninstalling gears, downloading the gears installer and running it. NOW the updated gears (0.5.29.0) installed and is compatible with Firefox 3.5. This was for Windows XP.
I tried this on Vista and gears installed fine through Firefox.
