> Did you remove the default config from those ports? Here's a related post that may help:
Yep, zero'ed the configs on both and added minimal lines necessary.
Since I'd not used the ge-0/0/2+3 before, I'll now test those ports non-clustered and without any pims.
So, about to start-from-scratch (again) with LOTS of traceoptions and try to suss it out.
I'll do a proper writeup. an hopefully not look too foolish, when I find the problem.