No HDMI Output from XPS M1530 to Dell 2407WFP

Hi,

I have an XPS M1530 and a Dell 2407WFP Monitor.  I have Windows 7 x64 installed fully updated through Windows Update.

The Symptoms are as follows:

When i connect the monitor using a HDMI to DVI cable the monitor instantly goes into powersaving mode. I have not used it for a while but it used to work! I checked the nVidia control panel and it was showing the monitor as connected and i could access all of the options, but the monitor was in standby.

so i bought another cable thinking my cable may have been damaged somehow, but when i connected the new more expensive cable it did exactly the same thing, I started thinking my monitor was broken.

I went back to the shop and got an S-VHS cable connected that up and my monitor came on so the monitor works, although it is running at S-VHS quality, which sucks!

So my monitor works, my graphics card works as it is picking up the monitor, also when i connected the S-VHS lead nVidia control panel told me "you can only have 1 external display connected at a time, please select the connection to use" then gave me an option of turning off the S-VHS or the HDMI!

Please can someone help, it is so frustrating, everything works, but the HDMI will not turn my monitor on!

Thanks