mfi(4) locking bug?

[jnemeth%victoria.tc.ca@localhost (John Nemeth)]

     I'm working on a multicore machine with an mfi(4) in it.  If I try
to boot the installation CD normally, it typically hangs when running
newfs.  If I 'boot -12' (i.e. no SMP {or ACPI}) I can install the
system.  However if I try to perform heavy disk operations (i.e.
pkgsrc checkout) on a system booted normally, it will hang at some
point.  Right now, the system is running with a drive connected to a
different controller where it has been doing things like checking out
and building packages, running build -j 30, etc.  for a week without
any issues.  Only difference between system that works and system that
doesn't is the disk controller in use.  Details on the mfi(4)
controller are:

# pcictl /dev/pci1 list
004:00:0: Symbios Logic SAS1078 PCI (RAID mass storage, revision 0x04)
# grep mfi /var/run/dmesg.boot
mfi0 at pci1 dev 0 function 0
mfi0: interrupting at ioapic1 pin 20
mfi0: logical drives 1, version 8.0.1-0038, 256MB RAM
scsibus0 at mfi0: 64 targets, 8 luns per target

Is anybody aware of locking issues in mfi(4) or have any suggestions
for debugging this problem?