If you find that you are unintentionally unlocking your lockscreen, then you might want to try out this mod by XDA forum member preludedrew.
This mod disables the capacitive menu button for unlocking the lockscreen. The mod has been tested on Vanilla Lockscreens, but should work the same on HTC Lockscreens. The XDA member warns that if you have any tweaks installed such the reboot button change then this mod will overwrite that.
If you require a fixed version to allow for this tweak, then preludedrew has requested that you post in the modification thread. Applying the mod involves rebooting into recovery and flashing the zip file.
For full instructions and to download the mod, head on over to the forum thread.___________________