Steven, congratulations, it really works now.
The problem was not any "abnormal" random mode, there are some constraints within my AutoDJ and with the tagging procedure, which might be evident, but of course you've got to think of that first.
a) the most important one: Auto DJ restiction "gap before the same artist can repeat" MUST BE 0 - it was 20 when I tested it the first time ...
b) you have to tick both tracks with the new flag - track 1 AND track 2 - not only track 1 (which I thought it is enough information ...)
c) if you want to do this, you can`t edit track 1 first and set your flag to YES, then save it, and the track 2 the same way - it doesn't work
>> you have to mark both tracks together, edit both, and chose "YES" for "keep tracks in sequence..."
But if you are playing those rules - it works perfectly - thx a lot