Ok, it's possible that this may be a problem of my own making - not 100% sure, but it's entirely possible.

I was having a separate issue where I was seeing very few groups listed on oQueue and it regularly dropped to zero, wouldn't allow me to connect to the mesh, etc etc. Upon reading another thread here, I found that if I don't join /trade or at least one chat channel then oQueue (sensibly) won't create it's own channel to avoid claiming channel 1.

Now that I've ensured I'm in a public channel of some kind, not only do I see more groups, I also haven't had a single instance of not transferring to another realm. This could be entirely coincidental, of course, but everything seems to be working AOK now and right at the same time I've made sure I'm in a public channel!