thanks for the hint!
I just upgraded to 3.0.2, but saving the configuration still gives me time outs.
In the meantime I have also seen time outs for MySQL- not very often, but sometimes. What's weird is, that on the same server there are various other containers using MySQL (actually Google SQL, so a SaaS) without any problems or time outs.
Could of course be that there's something wrong with my hosting environment, but it's hard to catch by these symptoms.