You're only 1 level back. Current I believe is 1.11. A lot of guys don't upgrade firmware and are on way older firmware than that. I'm not recommending flying on old firmware, just stating that guys do it successfully because they don't want to introduce new bugs (which has been known to happen, I guess).
The only issue might be if you're still under warranty (I'm guessing you're not) or have insurance, it may not be covered if not on latest firmware. Maybe 1 level back would be, but older than that, probably not.