Dell Latitude St External Screen Resolution

Hi

Have you got any experiences about connecting a Dell Latitude ST to an external screen via HDMI-DVI cable?

I've just installed this tablet with a 19" (and also with a 22"Wide one) LCD screen for testing purposes, but the max resolution is 1024x768.

After connecting the external screen, the Tablet's screen's resolution is limited to 1024x768.

In reviews, and forums I have read, that Dell Latitude ST can manage at least 1280x800 (it would be suitable for the external Wide screen), but on some sites people have mentioned 1366x768, and 1920x1080p max resolution also.

In my device, I have a Intel GMA 600, with 3068 Video BIOS.

Is there any chance, to set up external screen connection with better resolution?

Thanks,

Peter