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It is just recalculating levels from the experience you already had. Happens once for each skill after loading an old save.
From what I can tell, if the 1.1 beta had been available when you started that game, your 1h skill would have already been 81, and your athletics would have been 59. You aren't going to keep getting massive skill boosts due to some sort of bug. It's just that the amount of 1h/athletics/etc...exp you've gained is worth more skill points than it used to be, and the first time you utilize those skills in an old save will cause them to update to the 1.1 formulas.
thanks guys, seems legit - i seem to get the boost only once for each recently used skill. and it also looks like the boost was higher on skills that i used more extensively before