If you are an Orange HTC Touch Diamond user who has tried to update the ROM, you’ll know how annoying it is when you enter your serial number onto the HTC website and it complains that its not suitable.

If you have a HTC Touch Diamond that isn’t Orange branded, this post doesn’t affect you. You should be able to download the ROM from the HTC website or contact your vendor.

However, you can download a ROM directly from Orange. The URL is http://www.orange.co.uk/diamond/RUU_Diamond_HTC_WWE_1.93.405.1_Radio_Signed_Diamond_52.29.25.12_1.00.25.05_Ship.exe

This worked perfectly for me, however I recommend if you want to keep your contacts and text messages, you can back them up to your ‘Internal Storage’ using a program called PIM Backup here.  This too worked flawlessly for me, now TouchFlo 3D is much much more faster, and the phone feels generally all-round snappier when it comes to both 3D and normal performance.

Further information can be found on this XDA-developers thread.