I'm using something very similar to this with my raspberry pi http://www.ebay.co.uk/itm/1080P-HDMI-Male-VGA-Female-Video-Converter-Adapter-Cable-PC-DVD-HDTV-New-/170850801393. It seems to work, even though everything Ive read says it shouldn't. Not sure if it helps with your problem. It didnt work with my set top box, but does seem to work with my xbox 360.
Today should be the day my adapters arrive...fingers crossed. I installed a nightly build of OpenElec on the R-Pi last night, and from what I can see on my old SDTV, it's running fine..as good almost as on my dualcore AMD. This looks promising. Then I can copy over the plugins from my main system to the R-Pi, and it may be able to take over the home entertainment role (although DVD playback isn't there, so I may need to convert them to MKV or similar. Oh well, it stops little fingers playing with the discs..)
Would also like to try a second SD with Debian/Chromium installed, and see if it's any good for basic web, Google Docs, and Logmein..if so, it could replace the big PC for 90% of tasks. That'd be a power saving right there...
Then in place of the big TV upstairs (assuming all works, wii included), I'm contemplating reversing the screen on my old Inspiron to point outwards, and wallmounting it, using a big USB drive to hold Tiddlers favourite videos, and giving her in effect an embedded PC display, which would take up much less space, and with a wireless mouse and KB, would double as a useable basic computer when she's older...
Sad, isn't it...I know....
My adapters arrived last night..hooked the R-Pi up to the HDMI>DVI-D adapter, powered it up, and 20 seconds later, hello OpenELEC, in glorious 1440x900. Hurray! PC still on VGA. Wii with Wii2HDMI produced no image, but I suspect that's a "hitch it back to the SDTV, select HDTV/EDTV mode and try again"ism.
Now going to try a different distro..OpenELEC is good, but I can see another I wish to try..heh.
Darn Wii>HDMI didn't work. Sigh.
So, I've ordered an 18.5" TFT TV/DVD combi unit, with SCART, Component, HDMI, and VGA input, from Tesco for £80. Losing .5 of an inch from my current 19" screen is a nonissue, and that'll take the Wii (either through SD SCART or HD Component cabling), The R-Pi (through HDMI) and the PC through VGA, as well as integrating a DVD player.
The R-Pi is now running Raspbmc, as OpenElec has major youtube speed issues on it. It now flies, and has 4OD, 5OD, Iplayer, catchup.TV etc installed and running fine, so the PC has been relieved of that duty now.
I can see TVL coming after me again because I've purchased a new TV..heh..bring it on.