A little while ago I posted about my 500D having a dirty sensor and was quoted (sight unseen) around the cost of a new 500D body to replace the sensor
Well I am currently in Brisbane and thought I would take the camera in to a canon service centre to have it looked at. Was shocked at the techs answer. Apparently the hair like object is between the sensor and the cover. I thought the sensor was sealed from the outside world. Anyway was quoted $400 just for labor and more if the sensor is damaged.
Not happy.
We cleaned some gunk off Jen's camera at SV on the weekend. Put camera in mirror lockup mode and bulb, pressed twice to lock mirror and open shutter and used a blower to remove gunk.
I would give that a try first.
As Malcolm and the others have said a good blower job, than i use a good lens pen on my Canon 5D, it comes up a treat and dose absolutely no damage, the filters are tougher than led to believe.