Dell Netbook 910 won't play Itunes Rented Movies

I bought a Dell Mini 9 (Inspiron 910) Netbook for my son. Unfortunately I am having trouble getting Itunes movie rentals to play on it. I even engaged paid Dell tech support to assist with the issue, but to no avail. It seems there is an issue with the video hardware acceleration and the associated hardware and its ability to decode MPEG-4 video. This system has been re-imaged to just the O/S and Itunes/Quicktime and has the all latest drivers.

If you open a rented movie from within itunes, the play back windows will pop up and the movie title will appear in the title/control area and thats it. Itunes.exe will chug along at 15% cpu and essentially hang the rest of the machine (at least the GUI aspect) until I kill the itunes.exe process. This can be replicated 100% of the time. Alternative viewers of course will not work (rented movie files are encrypted). If launching directly from Quicktime using the "open with" function, all I get is a Grey screen - the movie time indicators at the bottom change values i.e. the movie is playing, but there is no image. I have followeed the itunes windows tuning suggestions (change Direct3D Video values, use safe mode (gdi only) etc., but to no avail.

Any suggestions, or do I just accept that I am stuck with A Dell Netbook that won't run a mainstream application properly?

PS, since this thing sat under the tree for 4 weeks, Dell refuses to take it back siteing 30 day return policy...mental note - do NOT buy a Dell as a Christmas present....