Well ROMs don't touch /data or /cache, so it's generally assumed that flashing a stock ROM won't wipe these by itself. A factory reset from the settings on the device itself after flashing the ROM should do that though, or else via recovery mode as you suggested.
Thanks, but this was not made clear, even as an experienced Android developer I was stumped for a while - maybe the assumption that all members know this, including newcomers, is not the best way - I'd add it there for the sake of redundancy, just in case (better it be there and repeated, than not at all). We have to remember that some members have only signed up and started their journey of device & Android hacking knowledge at the point when they purchase the hudl, and may have NO previous experience whatsoever. Assuming &/or implying that people should have to go wandering around Modaco & the general Android community to gain this unexplained knowledge of clearing partitions etc, is short-sighted at best, in my opinion.
I was expecting this (okay, in error) to be some sort of "TPT" (Total Phone Transfer) image, as used in other devices - again, yes - I was wrong, and should have remembered... but I'm human, and we err from time to time, especially us hardcore geeks with a billion numerical things to remember 24/7
I managed to get it all sorted doing a "sledgehammer to crack a nut" method in the end - I won't deliberate too much, as it's a dangerous, low-level method and posting it is not wise for newcomers, as it involves "rkflashtools" and zeroing from the beginning - 0x00000000 to 0x01000000 and then installing this ROM, which worked, thankfully.
Edited by glossywhite, 29 October 2013 - 10:04 PM.