I'm having a similar problem. In Tiny Speckles, I was able to see all group discussions just fine yesterday, today not so much. It says I do not have permission to view them. I am in two other groups (Glitch Strategy and New Streets) and I can see discussions in them just fine.
I still suspect perhaps sc803 was playing with member types...I'm not saying for sure...but I did this on accident in the Glitchodone Clinic once. Thanks for investigating, kev!
Hey folks- we found the problem and it is related to what Rascalmom noted above me.
When member titles are altered, it appears we don't properly account for group permissions based on those. We're going to fix it, but we can't do this one right away, I will ask if sc803 can restore the titles to what they used to be. This is a longer fix than we can do before then.