Running a fast mile as cardio?

I'm 5'6" and 147 pounds.  I want that lean and mean look and I'm down from 210 pounds from September 2007.  I want to keep losing weight and hopefully get to the single digits in bf % (not sure what I'm at right now, but I'd guess around 13-14%).  I currently lift twice a week, and do cardio three times a week.  On Tuesdays and Fridays I do a one mile run to kickoff my 45 minute cardio session.  I've always been dissapointed with my mile time back from middle school in gym class so to get a fast mile has always been one of my goals from losing weight.  Right now I run the mile in a little under 7:30.  I've heard mixed things on doing such an intense run as my heart rate gets pretty up there.  I seem to be stalling on the weight gain so I want to know if maybe running is the problem.

For me info...

my Fitday profile:
http://www.fitday.com/WebFit/PublicJournals.html?Owner=mcFreid

my most recent picture (around a week ago):
http://www.freidproductions.com/images/bodybuilding/6-26-08.jpg


Thanks much,
Michael