Novel way of selecting boot device on iMac

Just thought I'd share this as it took me a while to work out what was happening - iMac 17" would sometimes boot fine and other times it would come up with the boot device selection screen.

Eventually I worked out that this only happens when I have the light turned on.
It's an energy saving bulb and i think somehow it's intefering with the Mac. Also the wireless network will take longer to come up.
Changed the bulb back to an ordinary one and booting is normal.

So, if i want to start the iMac normally i have the light off, if i want to choose my boot device I turn the light on first

Cheers

Hugh

I'll bet it has something to do with the ballast in the bulb. We often see them emitting electromagnetic interference and causing issues with tube-based monitors here at work. That's funny though, thanks for sharing!