dstumbler showing 00:27:27

I'm using a Netgear MA401 (wi0: Intersil Firmware: Primary 0.03.00,
Station 1.03.04) in FBSD 4.7.  I get strange response with dstumbler
with the signal/noise readings.  I always see 00:27:27 for any
AP I try to look at.
I can see packets with it in monitor mode when using "prism2dump
wi0" and collecting packets using "dwepdump -a -w wi0".  Wicontrol,
however, does show sensible numbers:
p mode 1, Comms quality/signal/noise: [ 28 48 1 ]
p mode 3, Comms quality/signal/noise: [ 0 81 27 ]

I'm putting the card into monitor mode (prism2ctl wio -m)and
using the -o option in dstumbler.  I've tried this with a DLINK
DWL650 as well and I get the same results.

What does 00:27:27 mean?  And how do I get dstumbler to show
me the real signal readings?

Regards,
Al.
ps. How do I respond within an existing thread?  I.e. withouth
created a new thread (yes, it's a dumb question but I can't seem
to figure it out)