I have a feeling it doesn't work for HTC phones.
Edit: I am correct. This does not work on HTC phones due to NAND lock. You need to unlock NAND first. Here's a list of compatible and non-compatible phones.
Compatible
Samsung Galaxy S (All variants)
Backflip
Sony X10
Xperia Mini
Droid 2
Galaxy Tab
Galaxy I5700
Galaxy 3 I5800
Droid X
Samsung Acclaim
Cricket Huawei Ascend
Motorola Cliq
Huawei 8120
Hero
G1
Optimus T
Droid 1
Garmin Asus A50
Motorola Defy
LG Ally
Motorola Flipside
Motorola Milestone 2
Dell streak
X10 Mini Pro
Incompatible
Desire (requires nand unlock)
Desire HD (requires nand unlock)
Magic (unknown)
Evo (requires nand unlock)
G2 (requires nand unlock)
Archos 70 (unknown)
myTouch 3G (unknown)
Wildfire
Droid Incredible
Source:
[APP] z4root - xda-developers