I DID IT AS WELL!
I flashed the Taiwan ROM 1.10.709.01 into my EU (UK) Titan which I bought in Hong Kong. I did it because the Slider (ON/OFF) is missing in 'Settings/ease of access/Speech for phone accessibility', it only shown default value Off.
I bought : 1.) Y-Cable 2.) USB Adapter Female to Female (2 Pcs) 3.) One slot USB SD Card Reader
1. Use Android Tablet with 'Goldcard Helper' to get the CID for my 1gb Micro SD Card.
2. Reverse the CID number and go to
http://psas.revskills.de/?q=goldcard to generate the GoldCard.
3. Use GoldCard Tool to load the GoldCard.img obtained and 'patch MMC' to Micro SD Card.
4. Rename the HTC Titan (Eternity) Rom file to ETERIMG.nbh and copy it into the Micro SD Card.
5. Plugged the Power supply USB of the Y-Cable to Computer
6. Connected the SD Card Reader with Micro SD card slotted in using one of the the USB adapter.
7. Connected the Mobile USB cable using the other USB Adapter to the last end of the Y-Cable.
8. Press (Vol down + camera + power) at the same time, to enter Bootloader Screen.
9. Plugged the other end of the Mobile USB Cable to Mobile (HTC Titan) and Flashing begins and wait until it shows Completed.
Hope this will help.