panic with 5.99.55 starting postgres

[Darren Reed <darrenr%netbsd.org@localhost>]

starting postgres panic's my system every time with this panic:

panic: kernel diagnostic assertion "uvm_page_locked_p(pg
e " ../../../../arch/x86/x86/pmap.c, line 3214


From the pmap.c that was used to compile the kernel is this
extract, with **** being the line that panic's the system.

       pg = PHYS_TO_VM_PAGE(pmap_pte2pa(opte));

       KASSERTMSG(pg != NULL, ("pmap_remove_pte: unmanaged page marked "
           "PG_PVLIST, va = %#" PRIxVADDR ", pa = %#" PRIxPADDR,
           va, (paddr_t)pmap_pte2pa(opte)));

****    KASSERT(uvm_page_locked_p(pg));

       /* Sync R/M bits. */

Seen before?
Known?
Fixed? ;)

And perhaps more importantly, does anyone know when and where
this was introduced?

What's the last safe version of NetBSD to use postgres with?

Darren