Jens wrote me back last night.
"We're investigating this - some people were successful removing the DIMM, and we corrected a fault in the CF routines of Minimig. Only available for PAL Minimig at the moment. However, I found another error in Newboot that might confuse the memory on the extender."
"We have isolated a total of three causes that we will fix in the coming days. Luckily, it's all cores, so you will just download the updates and fix your hardware with that
It sounds like we're waiting for another Newboot at this point. Jens attached another Extender.rbf (1.11 PAL) file to me, but I actually found it also on the Forum-64 website (German Forum).
I'll attach it here also, as it seems to have helped some people. But that hasn't done the trick yet for me. Here you can see my current screenshot. The only difference is that the box w/ the error went away. Also, if you look closely, there seems to be some lines in the display. (Memory Issue?)
I guess we need to remember that we are "betatesters" at this stage (well you are, I'm still waiting for my board... 11:42am... where's the UPS truck?).
I went through this for a while with Jaqub's beta write-enabled core. Lots of testing, sending emails about errors, new cores back, more testing, more errors, more emails. It was certainly worth the effort though.