I'm using an 'old' laptop. A HP (Compaq) NX9420 with ATI Radeon Mobility X1600 graphics card. The TFT screen of the laptop does not work anymore. So I made a desktop of this machine by using an external Philips 22" TFT screen.
In Linux Mint 8 this works fine. I disabled the laptop screen and enabled only the Philips.
Now I want to use Linux Mint 9 and this screen does not work anymore. The Philips screen gives an unusable 'waving/shivering' screen. In the resolution 1440x800 (I believe) it is like a sea of waves scrolling from left to right. When I change to the right resolution 1650x1250 (Both 60Hz) the screen is in a high speed shivering wave which makes the screen totally unusable.
I have tried many restarts with live CD and with blank installations. ( I mean no update, but formatting the HD and a new install).
Just one time I had a nice screen like it has to be, so it must be possible to let it work fine.
It is not a problem of the monitor. I connected today the monitor to another PC (with Linux Mint 9 livecd and a NVidia graphics card) and I had inmediately a perfect screen. So it has to be a problem of the ATI driver.
I’m trying Ubuntu 10.04 too. This monitor/graphics driver problem is in 10.04 exactly the same.
I wish you succes with developping Linux Mint 9!!
Can anyone help me to solve this problem?