E3 and 12-60 swd strange behaviour at 12-18mm

I have an E510 and an E3. The 12-60 swd works perfectly with the 510 at all focal lengths but when its on the E3 it will not lock focus on distant objects at 12mm. If I zoom out it begins locking at a distance at about 18mm and all focal lengths beyond that. It will however lock focus at 12mm on objects within 6 feet!

Playing about with it I discover that at 12mm focusing at infinity I get the red flash for a focus lock but no confirmation beep and further pressing the shutter button will not activate the shutter itself. If I press in the lens release button the shutter WILL activate!!

I also have the 50-200 swd and that works pefectly on the E3 locking at all focal lengths in less than a heartbeat.

Firmware: Body 1.4 Lens 1.1

Anyone any experience of this behaviour or like to hazard a guess?

Mike