Hi there (roobarb?

this is a bit of a half-question, until I get a bit more info...
I have been doing a bit of H/W hacking on one of my Jogglers - connecting to two of the otherwise unused internal USB ports, as described eg. here:
http://www.jogglerwiki.com/wiki/Additional_USB_Ports
I've added one USB socket to the first set of points mentioned on that page, and hard-wired a small DAC (hot-glued to the back of the Joggler) to the second set of points. Prior to this work I had put the last Openpeak firmware on this Joggler.
The HW work seems to have gone OK and when I powered up the joggler the openpeak firmware started up. My next task was to put PNP III back on, and as part of that I used the birdslikewires reflashing tool, as successfully used several times. I have a 'known good'

USB drive which has the 'reflash/repart' file present etc.
This booted up on this Joggler fine, and went through doing its good work. I had troulbe installing PNP III for some reason, an ended up going through the reflashing again, leaving the Joggler on its own for an hour or so. When I came back the joggler screen was blank; I powered it down, and rebooted it. It came back up to the OpenPeak logo, but got no further.
Since then, the reflashing pendrive seems not to work at all. I'm now seem to be at the point where I have the OpenPeak logo coming up, but cannot get any further, even with my 'known good' pendrive and the reflashing SW. I was starting to suspect the pendrive but the MD5sums all seem to be fine. I remade the pendrive and tried another one, all without success.
I appreciate that the fact I have been doing some hacking means that there may be a HW problem here which is causing what I'm seeing ... but I doubt it, to be honest. I do have half an idea what I'm doing on the HW and can see no evidence of any actual problems with these mods.
So ... the point of this posting is to wonder whether I have to resort to the USB hub/keyboard angle. This will be annoying as I don't own either of these (although I can probably borrow them). I can understand (say) that having the DAC hard-wired might screw up the boot drive assignation - but in that case why did the reflash tool work OK at least once, and then fail to operate?
If it's of any use, I notice that when I power up the Joggler, the activity LED on the reflashing pendrive flashes briefly a couple of times, then after a few tens of seconds flashes again slowly, and then ... nothing.
Thanks for any pointers - and for the tool in the first place!
Cheers
J^n