Rockford 551x amplifier blowing main fuse

Here's my problem:  The main fuse of the power cord near the battery suddenly blew out.  I replaced it and it blew out after about 5 seconds of music.  Then started blowing as soon as I turned the key on.  I checked all the wiring and grounds and everything seemed fine.  I then unhooked both amps and the capacitor and the fuse was fine.  Hooked up the amp pushing the speakers and the fuse was fine.  As soon as I hooked up the rockford fosgate 551x that I have pushing the sub, the fuse blew after a few seconds, then blew it another time as soon as I turned on the key.  So, that is obviously the culprit. 

What could possibly be wrong?  The wiring seems fine, and this came out of nowhere.  Is there something wrong with the amp itself?  It's only about a year and a half old and I only drive the car on the weekends, so it's hardly ever used.  How can I go about troubleshooting this to find the real cause?  If there is something wrong with the amp, is this a common problem with these amps?  How much would it typically cost to get the amp fixed?  I'm in Dallas, is there anyone around that you would recommend to fix it?  Cost to fix? 

Thanks for the help guys...

I did bump up one notch higher on the fuse rating, but still had the same problem.  I haven't touched the gain since I installed it a year ago.  Maybe I'll try jumping up one more level on the fuse.

I would say that may be a bad idea, but I could be wrong, if you turn your gain down, and the fuse is rated at the right amperage for the amp and cables you are using I would not up the fuse amperage, because what may be causing the fuse to blow may cause a fire elswhere, or some less serious electrical problems.

You sould have the amp bench tested, just to make sure it is not the amp. 

You don't have to take my word on this one, because there may be some aspects that I am missing/overlooking, but what it all boils down to is if the fuse blows, that is your number one indicator that ther is an issue, and upping the amperage rating of the fuse is just going to let that issue get worse before blowing the fuse.

After all it is your amp, car and electrical system; you can do what you want, this is just a suggestion.

Thanks for the advice, I was a bit worried about upping the fuse another notch. 

Where can I go to get the amp bench tested?  Do I have to send it back to Rockford?  How much would that cost?  Is anyone else having problems with these amps?  I thought I bought a pretty good amp, but I guess not.

Have you removed and cleaned the ground for the amp? This is the most common fuse blower.