This issue has been on and off for a bit, most recently with Joerg. It seems related with an on-going memory issue our software has been generating which I am hopefully dealing with today.
Our site is moving to a slightly more performant/expensive yearly option that hopefully will deal with this and some other issues. It is also in need of some consolidation and clean up which I am hoping to perform over the spring.
Hopefully you will notice a more consistently performant site after today and hopefully the picture issues disappear as well.
mark
P.S. I am picking up the tab for this upgrade as payback for the great pleasure the society has given to me. Cross the fingers and hopefully things settle down.