If you restore SYSTEM DATA from a titanium backup you made from ANOTHER ROM THAN MIUI will get reboots....ONLY restore app data and apps. but ONLY if you bypass market sync or cancel all the downloads from the market then run the restore.
What else did you do? stock kernel? restore anything with Titanium backup??
if you restore system data with Titanium Backup from another rom you will get reboots.
If you bypass the setup you also bypass market sync.
If you flashed another kernel sometimes this breaks permissions for the files Theme Manager needs to apply the theme.
i did not restore system data from "ANOTHER ROM THAN MIUI"
i only restored apps sans data
Relax, you are not the only one having difficulties w/ theme manager. I couldn't get it to work yesterday, so I figured I would try and use the online themes, downloaded my theme 2.0 and started it,about halfway through FC. I was then able to restore the default theme without issue. I'm sticking w/ this until the next release.
Nobody is accusing you of anythng, they are just trying to help