question about pvresize not seeing newly added disk space

I am doing some work with lvm2 on our system with a 3ware 9550SX-12 card ...

LVM version: 2.02.01 (2005-11-23)
Library version: 1.02.02 (2006-01-04)
Driver version: 4.5.0

In particular, I wanted to experiment with the ability to add disks to an existing RAID-5 lvm volume on the 3ware side, and then using "pvresize" to make the additional space available on the system.

After adding a 200 GB disk to the RAID-5 unit on the 3ware side (14 hours!!!), I ran "pvresize" on the system, but it doesn't see the new disk space. I'm pretty sure that if I reboot, it will see it, but this somewhat defeats the purpose because I'm trying to figure out how to add space to a live system without downtime. Any suggestions on what to do to make pvresize see the new space?
In addition, it is interesting to note that using the -v option of pvresize, it seems like LVM doesn't know about the additional disk space:

lead 34 # pvresize -v /dev/sdb
Using physical volume(s) on command line
Archiving volume group "scratch" metadata (seqno 8). No change to size of physical volume /dev/sdb. Resizing volume "/dev/sdb" to 781205120 sectors. Updating physical volume "/dev/sdb"
Creating volume group backup "/etc/lvm/backup/scratch" (seqno 9).
Physical volume "/dev/sdb" changed
1 physical volume(s) resized / 0 physical volume(s) not resized

(In fact, the information "No change to size of physical volume" followed by "Physical volume "/dev/sdb" changed seems to me to be strange.)

Yet, running the "pvs" command, the lvm does indeed see the new storage:
PV VG Fmt Attr PSize PFree
/dev/sdb scratch lvm2 a- 372.50G 172.50G

(my apologies if this is a repeat message -- I think I sent it the first time before the subscribe request was processed...)

Jason.