Sometime after rebooting, I regularly get the syslog message

 /netbsd: mb_map full

one or two times, then the system hangs...
What can I do? Here's my system:

NetBSD 1.3.3 (HARDY) #0: Mon Jan 25 20:41:26 CET 1999
    lorenz@hardy:/share/mars/NetBSD-1.3.3/sys/sys/arch/i386/compile/HARDY
cpu0: family 5 model 2 step c
cpu0: Intel Pentium (P54C) (586-class)
real mem  = 66715648
avail mem = 64163840
using 840 buffers containing 3440640 bytes of memory
mainbus0 (root)
pci0 at mainbus0 bus 0: configuration mode 1
pchb0 at pci0 dev 0 function 0
pchb0: vendor 0x8086 product 0x122d (rev. 0x02)
pcib0 at pci0 dev 7 function 0
pcib0: vendor 0x8086 product 0x122e (rev. 0x02)
vendor 0x8086 product 0x1230 (IDE mass storage, interface 0x80, revision 0x02)\
at pci0 dev 7 function 1 not configured
vendor 0x5333 product 0x88f0 (VGA display) at pci0 dev 10 function 0\
not configured
ep0 at pci0 dev 11 function 0: 3Com 3C905 Ethernet
ep0: MAC address 00:a0:24:d8:d6:eb
ep0: 8KB word-wide FIFO, (undefined) Rx:Tx split, mii default mii, autoselect
ep0: interrupting at irq 12
ahc0 at pci0 dev 12 function 0
ahc0: interrupting at irq 11
ahc0: aic7870 Single Channel, SCSI Id=7, 16 SCBs
scsibus0 at ahc0 channel 0: 8 targets
ahc0: target 1 synchronous at 10.0MHz, offset = 0xf
sd0 at scsibus0 targ 1 lun 0: <SEAGATE, ST34501N, 0015> SCSI2 0/direct fixed
sd0: 4339MB, 6576 cyl, 8 head, 168 sec, 512 bytes/sect x 8887200 sectors
isa0 at pcib0
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
npx0 at isa0 port 0xf0-0xff: using exception 16
pc0 at isa0 port 0x60-0x6f irq 1: color
pc0: console
fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2
fd0 at fdc0 drive 0: 1.44MB, 80 cyl, 2 head, 18 sec
biomask 840 netmask 1840 ttymask 1842
WARNING: Disk appears to be old-NetBSD or FreeBSD.  See installboot(8).
boot device: sd0
root on sd0a dumps on sd0b
WARNING: Disk appears to be old-NetBSD or FreeBSD.  See installboot(8).
WARNING: Disk appears to be old-NetBSD or FreeBSD.  See installboot(8).
root file system type: ffs

-- 
      Benjamin <lorenz@dfki.de>