Radeon 9600XT - 256MB at high resolution giving problems

Hi. i spent quite a lot of money on a new graphics card (radeon 9600XT - 256MB) and now when i try and put my computer on high resolution settings more than (1280x1024) it goes all mad and puts everything to one side and on my games only shows part of the gamescreen.
it says that this is to do with my monitor but that should be able to support 1920x1080!
im pissed off cos i have bought this thing and now my computer only is marginally better so if anyone could give me some idea of what the f**k’s up i will be very greatful :a :a :a :a :a :a :a

What exact specifications does your monitor support?
I mean, the combination of maximum resolution and maximum frequency.

Furthermore, what Windows version are you using?
What driver for your video card (and monitor) are you using?

A bit more info may be helpful (and next time, please do not use a topic title ‘Grrrrr’, as it tells nothing about your problem and people may ignore it for that reason).

Ok, i looked at my monitor info and i dunno what parts are important so ill just put all of it:
Display Data Channel (DDC): Supported
Display Name: Dell E151FPp
Max. Reported Resolution: 1920x1080
Max. Reported Refresh Rate: 75 Hz

I am using Windows XP and i have the latest drivers from the radeon website for my card, but i have no idea about the monitor, sorry

Sorry for not puttin it before but i aint too good at this kinda thing