Firstly which version of Start8 are you using? 1.03 or 1.1 beta?
I assume by change PC settings you mean "PC Settings" link on the start menu?
A quick test here is not showing any problems with this and yours is the first report of anything like this. Have you installed any other products which may customize Windows 8 such as Decor8 as I doubt Start8 itself is causing this problem. As a related point, there is a potential problem with Windows 8 and it corrupting something after changing the login screen image, did you perhaps do this recently?
I also quickly put TrueCrypt on a 64 bit test box and created a volume from a partition and then set it to auto mount on login by making it a favorite and then ticking the box to make it auto mount on login. With or without Start8 this causes the password prompt to appear automatically about 10 seconds after startup.
Are you setting it to automount in some other way?
End of Neil's quote
1. 1.03, since I never run beta software.
2. I mean "Change PC settings" in the "settings" in the "charms bar", or from the Windows 8 desktop (control panel -- can't remember where exactly). It does nothing at all. It has ceased working.
3. Absolutely no other products that change anything of any kind, and a very clean installation without any "fancy" things.
4. Haven't changed any login screen image.
5. Well, it's set up so that it doesn't ask for a password but uses the main system disk encryption's cached password. Since I installed Start8, it has stopped mounting this. There is no question that something that Start8 is doing is causing this. I of course hope that TrueCrypt will release a version that supports Windows 8 properly, but again, this seems to be Start8's fault in some way. Perhaps indirectly.