I've just upgraded to DasBlog v1.9.7123.653. My apologies if things have been (and still are!) a little temperamental around here!
Now, to get the config tab working again...
Update: Edit tab wasn't working because there was an entry in site.config which was referring to the previous version of the FreeTextBoxAdapter. I removed the entry, and it all worked again:
<EntryEditControl>newtelligence.DasBlog.Web.FreeTextBoxAdapter, newtelligence.DasBlog.Web, Version=1.9.6264.0, Culture=neutral, PublicKeyToken=null</EntryEditControl>
I've also taken this opportunity to use the dasblogupgrader.exe tool to remove all the pingback spam that was cluttering up a lot of my pages...