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I have used GMail Manager successfully for years but just recently an issue has cropped up...I have two Gmail accounts - one continues to work perfectly but for the other, I only intermittently (rarely!) see email 'snippets' when I mouse over the icon in the status bar. Shame as it's always been great before...this might be a GMail setting (used to be an issue with Buzz) or it might be an add-on issue...not sure...this occurs on Firefox 21.0...