We recommend using straight cables instead of converters/adapters. Sometimes those converters/adapters may not provide all the features the original port can provide. Please check this link for more information about display resolutions http://www.intel.com/support/graphics/sb/CS-022544.htm
Did you ever get any answers with this problem? I see you got some really useful advice from Intel ;-)
I have a similar setup to you in that I have a HDMI output from my AV Receiver to a Component converter box which is connected to my HD CRT TV.
I'm currently running a PS3, HD Set Top Box and now my HTPC via HDMI into the receiver.
I have been working with the custom resolutions using the Intel Graphics and Media Control Panel to no avail. The specific settings I am looking to set up are as follows:
The thing that's interesting is that screenshot is taken from my MacBook Pro which has an i7 with HD 3000 graphics too. The MacBook Pro is connecting to the TV in exactly the same way as the HTPC and like the HTPC did not have the 1080i resolution available. The fix for the MacBook was to use a program called SwitchResX, which generated the screenshot above. So now the MacBook displays 1080i on my TV.
EDIT: With a bit of testing I have discovered that the Thunderbolt/DisplayPort on the MacBook Pro only works with the AMD Radeon HD 6750M card. Either way I was still forced to manually add the 1080i resolution so why can't this be achieved with the Intel Drivers
Keeping that in mind I tried to do the same on the HTPC using the Intel Graphics and Media Control Panel but the best I could do was this:
The problem seems to be that you can't change the Horizontal Scan Rate or the Pixel Clock and therefore you cannot get the correct configuration for 1080i. Please note that I have tried the Basic Settings tab and that didn't work either.
My question is around the custom resolutions section and why I cannot enter the required resolution into the Windows driver.
I have since found this which would lead me to believe that I need to speak to my Motherboard manufacturer: http://www.intel.com/support/graphics/sb/CS-029478.htm
Message was edited by: Kris