thanks a lot for your help. The problem in my case is in fact the headline. The tableview-control does the row number handle different if the flag for head-line is set. So the calculated index of the whole table has to be reduced by one. if you don' t set the flag for heading the calculated index matches directly.
Yes, I know, this is also documented above. You have now mentioned this three times, so you understand the issue (for which there is no fix) and you have a workaround. What then is the problem?
It might be possible that somewhere in this threat - which has no ending in scollbar (about 458 posts, which not only deal with the problem itself) - is written that it is an issue in ai2 without a fix. In fact I did not read this part of the post or i did not find it.
I also do not know what exactly i have written 3 times. That what I wrote was what i found out by myself except the part with tr:nth-child which i found in a threat from you. for all other side effects i searched the error in my logic without thinking of an error somewhere else.