you don't need to downgrade at all to go from HR-->YMR. They are both based on stock zvh source, and thus, you can just backup with Titanium, Move YMR and the assorted extras you would like for it over to the root of your sd card(not in any folder, just in the default directory) boot into recovery, make a nandroid backup(backup/restore), wipe cache, clear data, clear dalvik cache(under advanced), than choose install zip from sd card, choose Your-Mom-ROM.zip from the list(using volume keys to scroll up and down, menu button to select, and back button to go back).Than go back to the main menu, choose reboot system now, and wait. It may take a while(a loooong while). That's ok for the first time. Log in with your google account, and wait for about 10 minutes for the ROM to settle. Than reboot into recovery and flash the other goodies(3 way power down mod, updated gingerkernal)and boot back into android. Than install all your apps from the market, and than restore the DATA ONLY from titanium. DO NOT RESTORE APPS AND DATA!!!!!Post any troubles.