Is is worth taking it to a Canon agent and arrange for it to get a service? I know Canon do this in the major centres, but depending on where you are you may have to get a camera store to ship it on your behalf. It might be worth a phone call to Canon in South Australia and see what they say. They can only say no.
Another thought...is the firmware up to date? Check with Canon to see if there's been a release that fixes the problem.
Failing that, DP Review has a number of threads in their forums about the 450D here
https://www.dpreview.com/forums/1031...=canon_eos450d
and while I haven't looked at them all, there might be something that addresses the issue there.
Good luck!