Do most Canon cameras have a problem of majenta coloration on pictures.....may be after 2 yrs(or so) of usage?

Sounds like your camera's CCD is dying:

http://www.imaging-resource.com/badccds.html

"The problem can take any of several forms, but all involve severe color shifts and/or severe distortions of the image. The images below show two examples (courtesy of Konica Minolta) of what the problem might look like, if your camera falls prey to it. In the early stages of the problem, the camera may still capture recognizable images, but with a washed-out appearance and a strong magenta or green tint."

they say to format your memory card often

that may help

plus go into menu and reset camera

I have 3 canons and have no problems

If you want a really cool camera.

I suggest getting a Nikon d40x.

atleast i dont have such kind of problem