There's another bug related to that line 856, but this time with another number than the ones I found when looking for prior reported occurences with the Search feature.
I did a search for "on *:input:*" without the quotes, set to scripts and popups, 3 weeks.
Warning: Compilation failed: nothing to repeat at offset 25 in /home/www/showflat.php on line 856
And all posts empty again, no matter what search result.
Greets
