Sticky DG and DME distance question

Couple of questions.

Went up to practice some ILS approaches. While being vectored for my
approaches, my DG kept sticking through the 270 heading. First time on my
initial approach and the second approach. Third and fourth approaches, DG
acted normal, though seem a little off compared to the magnetic compass.
(gave me good practice for partial panel approaches!).

Also, my header bug seem to be frozen, couldn't move it at all. I ended up
using my magnetic compass and VFR GPS for my primary navigation and
tracking.

I had this happen once on the ground a long time ago, and never gave any
thought as it performed flawlessly in the air since. Vacuum gauge was
exactly where it should be.

Last thing I want to worry about in the clag is the DG. Is the DG worth
overhauling or just getting a new one???

I went to http://www.aircraftspruce.com/menus/in/gyros.html to see what
prices I am looking at, and it seemed all over the page in price. This
would be a part obviously I don't want to cheap out on, but I don't want to
buy a part that is has something in it I never will need.

Suggestions much appreciated. I figured to post this time b4 going out on
the limb.

DME question. While on my VOR Alpha approach back to MBO, ATC reported me
3 miles from the VOR, and my DME reported me 4 miles. This is the first
time I ever had a discrepancy that much. Anybody know what gives. My DME
seemed correct as it reflected 5 miles to my airport.

Allen