All the errors, disappearing topics, site 'suspensions', downtime and SQL bugs are now gone completely, all of them attributable to the host that has now been dropped in favour of the older, stable host that we've been with for the last two years, and that we will probably be staying with for the forseeable future at least.
To rub salt into the wound, having been locked out of the shell interface on the new host, I haven't been able to transfer any posts or private messages that have been made on the board during the time we were with them. Thankfully this only amounts to four days worth, and I have been able to save the information for any new members who joined during that time, and will be adding that to the forum shortly.
I'd like to apologise for all the problems that have dogged the site for the past week, and thankyou to everyone for sticking with us during this time.
Everything should be more or less back to normal again now.