I have the same thing happening on my equipment. Im guessing the TCHANGE stands for topology change but I dont see any role changes in the bridge port status...

running 7.13 on a netpower16P

I have seen the same issue crop up a couple times now. I've experienced this issue running 6.48 but I believe this may have also happened as far back as 6.47.3.

Rebooting the wireless wire's seem to resolve the issue.