Pesky Bunnies and other 20D gripes

My excitement over my new Canon 20D digital SLR has started to die down a little bit now. Yes it takes beautiful pictures. Yes it is super fast to fire off shots. Yes it takes my normal Canon lenses. Yes it is great value for money. However not all is good in the digital SLR garden of Eden. The first problem I had was chromatic abberation - rainbow circles around bright lights, especially at night. This happened almost immediately after getting the camera doing one of my usual night light shots. After a brief conversation with Canon technical support I was told that wasn't usual, so ordered a replacement from Amazon. Then I had another conversation with the more advanced Canon technical support and they told me it was to be expected with that lens, the standard lens that comes in a kit with the camera. So no solution there other than fork out for another lens. The second thing that's bugging me a little is the 1.6x conversion factor. This changes your bog standard 28mm lens to being 45mm - quite different, especially as I prefer 28/35mm lenses in general. On the plus side this is great with my 200mm lens, especially for pictures of the moon or the Manhattan skyline. Now we're onto the third problem - UBOs, or unidentified black objects. These are generally circular dots that appear on images all over the place. Generally you won't notice them unless you take a picture of a sunset or sky in which case they tend to stand out like a sore thumb. I've been plagued by a particularly big one over the last few weeks so now I've gotten reading about the need to clean the sensor regularly. Herein lies the problem, and it's not a problem reserved for the 20D alone let me make that clear; with a film camera a different piece of film from a fully sealed, dust free container slides past the lens, is exposed and then developed - simple, however with a digital SLR there is only one piece of 'film', the sensor, and once that gets dirt on it you have to take it off yourself - there is no other way. After a bit of reading the best advice seems to be to use a Sensor Brush, based around the biotech industry's need to clean slides perfectly every time. Having tried unsuccessfully to use my little hand blower tool that is definately my next step - as what looks like a perfectly clean sensor to me comes up with umpteen dots on a magnified picture of a blue sky. The other major piece of advice is to avoid taking your lens off if you can!