You need to name it ruu_signed.nbh and put it in the same folder as the ruu.
I just ran it with on of the O2 splashes and then re-flashed my previous rom. It went A-OK (after the reset, it just hung on the splash screen-no red numbers, nuthin, so I know it worked). I've been having this weird issue for a while now where some files in \windows and its sub-directories will become corrupt after a soft reset. When it happens, they look like a folder (not a file); see below. It happens every time with UCWEB-there are some files in a folder called CDDATA that get messed up after each soft reset (it doesn't happen if I have UCWEB in \program files, only in \windows, but that's where I prefer it). It's not really the files that are messed up, but the directory. If I rename it from CDDATA to something else (then name it back to CDDATA), then the files are recovered. I have the exact same issue with the new Bing app. The XAML folder (in \windows) gets messed up after every reset, and can be fixed by renaming it twice. There are also a few random files in \windows that get messed up occasionally (a few text files, and weather.dat, which is a weather dump for the Weather-2-Go plugin).
Anyway, long story short, I was hoping that Task 29 would magically make this issue go away. It didn't, lol. I always hard reset before and after flashing, so maybe I didn't need to run it. I've never had any other issues (like S.O.D. or random hard resets) that plague other users.
I'd also wondered if running Task 29 would alter the bad and reversed blocks on the device. No dice, I still have the same 7 bad blocks as before.
BLOCK 123 (0x7B) is bad block
BLOCK 162 (0xA2) is bad block
BLOCK 1104 (0x450) is bad block
BLOCK 3188 (0xC74) is bad block
BLOCK 3201 (0xC81) is bad block
BLOCK 3236 (0xCA4) is bad block
BLOCK 3733 (0xE95) is bad block