Speaking of "server problems", I got bit by a server problem that stopped my computer from downloading PPSE tasks.
But the server with the problem was NOT the PrimeGrid server. It was the "Monkeys" server, aka goofyxgrid.
It's supposed to be serving up NCI (non-compute-intensive) tasks, but it sent my main computer four tasks that were incorrectly lacking the NCI designation. As a result, BOINC allocated all four cores to these Monkey tasks. Normally they don't use any cores at all.
Since the Monkey tasks were occupying all the cores, BOINC wouldn't run any PPSE tasks.
Goofyxgrid just recovered from a major outage, and there's been some configuration issues as he gets everything back up to speed.
So if you're also running "Monkeys", be warned: a configuration issue on his server may prevent you from running normal tasks from other servers, including PrimeGrid.