Can someone here help me operate a staple gun? I just bought my first one,
I've read and re-read the directions and still can't get the staples to go
flush to the wood.

The one I bought is the Arrow ET2025HD combo staple / nail gun. It's made
to staple over wire, and I removed the small metal guide in the front so
that it should shoot the staples flush to the wood like the instructions
said, but they're still sticking up about 1/8 inch, not much different from
before I removed the guide. I'm using Arrow T20 3/8 inch staples, and
the wood is pine. I'm stapling screen to the wood. The instructions also
say to twist the top, and it has a plus and minus, but it doesn't say what
this does, and which way does what.

I hate it when a simple tool like this can make me feel stupid, and I don't
want it to win.

What else should I be doing to make the staples lay flat against the wood?

Thanks!
Pat