Fuse blown on RB-1080 with new pair of DynAudio's

Hi all,

I purchase used RC-1090 and RB-1080 here last week. I've been using them with a pair of old speakers that I have. They work fine so far.
This weekend, I bought a brand new pair of DynAudio Audience 82 + Audioquest Dimondback XLR balanced interconnection + cheap 18 gauge speaker wire from RadioShack (temporary until I get better speaker cables). I hooked them up and listened for about 3 hours. Then I read somewhere that the speaker wires should be the same length, so I shut them down and trim 1 of the longer speaker wire to have the same length as the other. When I hook them up again, I got no sound to both of the speakers. I also noticed that when I hook the wire to 1 of the speakers, I heard some popping sound from the speaker. I went through all the steps that I know of to try troubleshooting the problem. Finally I pinpointed it down to the amp (RB-1080). The internal fuses were blown. Through out dozen of time trying connect/disconnect the speaker wires, I don't think I ever let the +/- part of the wires touched.
I bought some replacement fuses. But the fuses just kept blowing. At one time I was able to listen continuously for a few hours. But as soon as I turn the amp off or turning it on, the fuses blown again. I already made 2 trips to RadioShack and blow 16 of them fuses. Finally, my amp blows the fuse on the back of the amp. So as this point, I'm not sure what I should do.
So here are my questions:

1. Is there something bad with my new DynAudio speakers? How can I tell whether they are still in "perfect" condition (as they are brand new)? Have I done any damage to them? Is there a way of testing and now for sure?
2. Is there a minimum length of speaker wire required? Are the cheap 18 gauge speaker wires the culprit?
3. What should I do next?

Thanks in advance for any suggestion.