Thanks for your replies. So far my customer just sent me this brief Profiler Trace; I hope I could log on to the system ASAP so I could check the QEP ...

"Memory Pressure" might be indeed a problem here - luckily a temporary one, since at the moment this customer is running on a small virtual "interims" box ...

But anyway: except for increasing the memory (if possible, have to ask), there's nothing I could actually do to improve this?