I'm running WLM Version 2011 (Build 15.4.3555.0308) under Win Vista/64.  A couple of times recently, I've received a notice on my screen informing me that my 'memory is low,' and that I should close and re-open WLM.  On both recent occasions, I wasn't doing anything noteworthy in the program; all mail had been read and filed or discarded, and nothing was waiting to send.

What is the typical memory usage for WLM?  Right now, with the program running but simply sitting there, Task Manager tells me it's using 92,460 K of "Memory (Private Working Set).  Is this typical, and why should it change with nothing happening?