This has been the subject of quite a bit of discussion on the DPReview forum, and it is believed that the following will work:
1) Set camera to Manual Focus
2) Switch to Mode SP, Landscape
3) Cover lens, and press the AF Assist button
4) The camera will fail to focus with the "!AF" error
5) The camera is now set at infinity AF, change to preferred mode and take pictures (but leave manual focus on)
marius@marius.org