MAX_KMAPENT?

I have a NetBSD 2.0.1 box that died last night with the following error 
on the console:

panic: uvm_mapent_alloc: out of static map entries, check MAX_KMAPENT 
(currently 1114)
Stoppped in pid 15.1 (pagedaemon) at netbsd:cpu_Debugger+0x4

Of course, things are fine after a reboot. 

Trying to be the good scientist, I need to get a better understanding of 
what 'MAX_KMAPENT' is and what 'uvm_mapent_alloc' is.  If anyone can 
help, I'd really appreciate it.

I have to assume that there is some sort of resource issue going on 
here, and I don't want to just reboot the box and forget about it. 

Thanks so much,

Michael