just to add some clarity as it's been confusing recently - there have been 3 recent problems, all different causes but with similar symptoms, explained below:
1) Autoplay broken on iphone/ipad -
Apple seem to have banned it, so user must press something first. Nothing i can do.
2) Player didn't advance to next track or broke after a click or two -
This was Fixed in 1.8. The problem occurred after updating to wp 3.5 (jqueryUI scripts changed). A previously silent error suddenly decided to throw a fit (fair enough i guess!).
3) Player didn't autoplay/time displayed as 'NaN' -
This was fixed in 1.8.3. The problem occurred after a recent flash update that killed jquery.jplayer.1.2.0 which I was still using. The plugin now uses jquery.jplayer.2.2.0.
Finally, Laura, I've no idea why reposting your players worked, i've never seen this before, and if it's exactly the same shortcode then it really shouldn't change anything. I'll close this thread for the mo, but if it happens again, or you still have issues with it please let me know!