Does anyone know why this is happening? I mailed this priority last Saturday which was 3/15. I checked the DC to see where it was because I thought for sure it would be delivered by now.

Bullet Processed, March 22, 2008, 2:19 am, NASHUA, NH 03062
Bullet Processed, March 21, 2008, 1:50 am, BOSTON, MA 02205
Bullet Processed, March 20, 2008, 3:19 am, NASHUA, NH 03062
Bullet Processed, March 19, 2008, 2:38 am, BOSTON, MA 02205
Bullet Processed, March 18, 2008, 9:58 pm, NASHUA, NH 03062
Bullet Processed, March 18, 2008, 2:04 am, BOSTON, MA 02205
Bullet Acceptance, March 15, 2008, 9:22 am, ELLSWORTH, ME 04605

Why does it keep bouncing back and forth between Mass and New Hampshire??

I would contact your local PO. Either stop in with the number, call or use the contact us from usps.com.