Kallie:
can you give us an idea of the different power or swr readings you get on
the same frequency?
are they drastic? and have you had an opportunity to get a sited ham to
check with a regular swr/power meter just to see if the readings are
similar?
If the power readings are within about 5 watts of each other, its probably
just normal error rate, and if the swr readings are within .2 or .3 of each
other, then that's probably normal as well.
Its usually a good idea to take at least 3 readings about 5 seconds apart to
get a good average swr or average power output reading.
Keep the radio keyed for about 15 to 20 seconds and hit the power button on
the meter every 5 seconds,.  take those numbers add them and then divide by
how many readings you took and you will get your average.  Do the same with
swr.
If your averages vary signifigantly from day to day, then it may well be a
defect in the meter.
But if you find that averages stay the same while showing a bit of
fluctuation, its probably pretty good and not something to be concerned
about.
Also, is your reflected power high? if so then there could be problems with
coax or antenna resonance as well.
73
Colin, V A6BKX