Iann
Now I think of it can you also collect a similar log with the dom0_mem workaround in place, for comparisons sake.
Are you able to rebuild the kernel with CONFIG_XEN_MAX_DOMAIN_MEMORY=128? If so then a log of that boot forcomparison would be very interesting.
If you don't know how let me know and I'll build one for you.
If you find the time, please build one. I hope to be able to test it soon. -- Rik