FreeBSD-9 crash at swapctl -d

[Wojciech Puchar]

repeatable crash when turning off my 9GB swap partition (of which 0 bytes 
was used):

Dump header from device /dev/ada0b
  Architecture: amd64
  Architecture Version: 2
  Dump Length: 198971392B (189 MB)
  Blocksize: 512
  Dumptime: Mon Mar  5 09:29:41 2012
  Hostname: wojtek.tensor.gdynia.pl
  Magic: FreeBSD Kernel Dump
  Version String: FreeBSD 9.0-STABLE #0: Sun Mar  4 22:58:17 CET 2012
    root at wojtek.tensor.gdynia.pl:/usr/src/sys/amd64/compile/wojtek
  Panic String: blist_meta_fill: allocation too large
  Dump Parity: 606467164
  Bounds: 0
  Dump Status: good


any ideas?