My Google calendar is stuck on the current month, and edits to events don't save. I have FF 21, and Win7, on a Dell Latitude E6400. I have the calendar as a pinned tab, but Tools > Options > General > Use Current Pages doesn't recognize it..
Many site issues can be caused by corrupt cookies or cache. In order to try to fix these problems, the first step is to clear both cookies and the cache.
Note: This will temporarily log you out of all sites you're logged in to.
To clear cache and cookies do the following:
Go to Firefox > History > Clear recent history or (if no Firefox button is shown) go to Tools > Clear recent history.
Under "Time range to clear", select "Everything".
Now, click the arrow next to Details to toggle the Details list active.
From the details list, check Cache and Cookies and uncheck everything else.
Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).
Do NOT click the Reset button on the Safe Mode start window or otherwise make changes.