same problem here with the random rebooting all the time marc, twice in the same day, maybe three sometimes! then even randomer is a problem with the phone signal not starting up. when the phone reboots by itself a message comes up when the phone is back on saying something like "phone process has stopped" and a button underneath saying force close.... no signal... only a reboot will get the phone signal back working again... but that thing you mention about the trapped in rebooting sequence happens as well. it happens 100% of the time when i try to reboot from the phone signal problem.
i dont even bother trying to reboot now and just know to pull the battery when it happens

its a shame really, if feel the same way as yourself Terence, out of all the smartphones ive had the last 3 years i think ive almost found the perfect phone, i dont think i could go back to the slide out landscape keyboard after using the blackberry style.... its just all the dam rebooting and slowness gets in the way of it being the perfect phone.
hopefully some other company will come out with a similar android phone soon, id swap over straight away