Dusty Images?

I thought I'd see if I can prod you pros into sharing some info that might help me (and hopefully others) on dusty images.

Last night I took my camera out for about 1.5 hours to take some extended exposure shots (I think time-lapse is so cliche, but I guess that is what it was) and see if I couldn't get some star streaks among a few other things. Well, I managed to get a couple, including one 46 minute exposure. Once I got home and viewed the images on my computer I was able to get a few good streaks, but my images were totally ruined by thousands of little red and blue specks of dust (I guess it's dust, but I'm not sure).
I was shooting with an XTi and the standard lens kit that comes with the body. ISO 200, f/stop 11 (seems to be the sweet spot for other shots with the camera/lens) 18m focal point-manual focus. At home I was looking at the images on an HP High Def LCD monitor. The monitor sometimes throws some funky looking things on images that aren't there when I look at pics on other screens, so I thought it could be that--but I doubt it.
I've had the camera for a little over a year and never had it professionaly cleaned, so I'm wondering if I've got dust on the sensor. You guys have any words of advice on this?
I'll try to upload the pic tonight when I get home so I can post for you guys to see.
Thanks!

I really can't help with whether it's noise or dust. What I would suggest is getting a Giottos "Rocket Blower". I keep one in my camera bag and use it to blow out the sensor when changing the lens. It's good for just blowing dust off the lens, too.

I have a small in my bag and a large at home.

Win

http://www.bhphotovideo.com/c/produc...r_Blower_.html

Dust spots from particles on your image sensor will appear as grey or black blurry spots, not brightly colored lights. What you are probably seeing is long-exposure noise. I don't have a Canon like yours, but DSLRs often have a long-exposure noise reduction setting available.