I wouldn't say a common name, but it's not unique.
I've contacted a couple of lawyers, one of which has got straight back saying they can help find out if I am on a blacklist, why and for how long. Appealing it will depend on the circumstances. I'm going to ring the Thai immigration tomorrow morning and see if they can shed any light on it first however.
The land crossing would be a preferable option, but I'll try to get to the bottom of things first. We were planning to stay for a year, so wouldn't be traveling light. There are also lots of planning/preparation to put in place before we leave so chancing it would be a gamble.
Thanks for your comments.