SMP-PPC spinlocks in 7.2.4?

Hello.

Previously, I had some problems that appear to have been caused by the smp-ppc spinlock issue that was in the early 7.2
series. 

The machine is a dual-800 g4, 10.1.5, using a libpq based client through local domain sockets.

The last few days, I've been dealing with a client who has drastically upped their usage of the database and in doing
sois causing deadlocks. I was running 7.2 or 7.2.1, I upgraded to a locally compiled 7.2.4.  I've run a vacuum full on
thedatabases.  

Sometimes the clients have a ps ax status of async_notify, sometimes there's just a stack of selects and updates that
gethung. (I'd estimate 6 deadlocks since Saturday).  It seems to coincide with times of extra activity, such as when
thedatabases are being backed up with pg_dump.  

I've also noticed the following in cron logs from nightly vacuums

NOTICE: Rel pg_attribute: Uninitialized page 59 - fixing
NOTICE: Rel pg_attribute: Uninitialized page 60 - fixing
....

Is there anything I can do to debug this?  I'm willing to give it a shot, but I'm also rapidly preparing a single proc
linux/intelmachine to take over db duties. 

eric