Oil pressure guage

I've had my '05 X for a couple of months now. I have noticed that the oil pressure guage moves quite a bit. I will start my X and the needle is right in the middle where it should be. When I get to wherever I am going I look at the guage and the needle is right above the bottom line. It never goes outside the "normal" range but it gets really close. When I check my oil it is full.

Since it has not left the normal range I haven't called the dealer yet. Does this happen to anyone else?

http://www.xterraownersclub.com/ubb/ultimatebb.php?ubb=get_topic;f=78;t=000541#000000

Here you go...

Thanks... Sorry I didn't mean to post this in Parts and Accessories :x