Trouble with external monitor resolution in 6.2

I have been among the select few quite pleased with 6.0.1, as I have been able to install everything needed from Debian repositories or other downloads. One of the especially impressive features of 6.0.1 has been the way the system, using LXDE, has tackled different screen resolutions 'automagically'. For instance, I write this on a laptop with 800x1280 screen, but using a 1200x1920 external monitor, with full resolution and no problems.

In 6.2, running from the DVD version, I have not been able to make this work, tried kde, gnome, fluxbox + 'default'. No way, but I haven't tried with resoultion cheatcode, because that should not be necessary. Because this is so important for my use, I think I will have to stick with 6.0 - but several of the basic packages there are in need of updating now. And I would like to start from the DVD release.

Is there any easy way out for me? Or will the best way for me be a remastering based on my 6.0.1 install?

Standard Gnome or KDE won't work for me with correct resolution 1920x1200 in 6.2, and LXDE also hangs, even natively on my Dell Vostro 1710 with no external monitor. But I can make LXDE work if I omit Compiz fusion. Which is done with the cheatcode no3d. But I haven't been able to find out how this initialization is being done, so the 6.2 X init is surely lacking a lot in transparency.

Just trying out a new Benq G2420HD 1920x1080 monitor, and it works (well, almost) nicely with Knx 6.2 and a Fujitsu-Siemens Amilo pro 3405 when the cheatcodes no3d and screen=1920x1080 are used.