Okay, I have been restarting my device a lot with all the setting up, installing, and registry editing. I am sick and was sick from first boot up, of the startup/shutdown sounds. Who has found a way to kill them, I have not had much luck in the registry. I even killed the one in Control Panel > Sounds > Shutdown, but that did no good. My phone is already decerted (completly app unlocked), so I know that isn't the issue. Any insight into this one. Heck even my little reg tweak program isn't able to disable those sounds (even tells me not to bother trying with that program), and I can't find the strings to do it manually.

I'd be interested to see a screenshot of the HKCU/ControlPanel/Sounds key. Obviously I don't have a 3125, so I can't help much, but I had a similar problem with the Q. I tried altering the Startup and Shutdown values, but it still reverted back to the sound. In the end I think I ended up deleting the value completely instead of altering it, and it went away.

Well the Control Panel>Sounds keys are just like every other phone, that is why I was getting frustrated. I did find a solution after IM'ing someone who I thought might know. Bare with me folks as I am still getting used to WM5, and the smartflip didn't have startup/shutdown sounds. It was encece that got me started in the right direction. I found it in the registry under the following strings.

HK_L_M > SOFTWARE > HTC > Shutdown > WAV
I simply deleted the value and replaced it with *none*

I then did the same for
HK_L_M > SOFTWARE > HTC > Startup > WAV

Also noted that this is where the Cingular Splash screens are located incase anyone wanted to change those as well. That was fun

Oh, and I tried taking some comparision pics, but I will have to wait until daylight as the lighting in my apartment sucks.