So if it is happening with both lenses, I would assume a problem with the camera. I would think there is something being interrupted with the communication between the camera and the lens where the focus motor is not being engaged. You might try looking at the Canon forum on dpreview.com to see if anyone has had this issue. (I don't have a Canon so I'm not much help with specifics to that camera, sorry.)
I hope you can get it fixed soon...I am sure it's really frustrating!
Olympus E-3 SLR