I've had a few pictures with flare at 24mm on the 24-105. Not the dreaded "rays of heaven", just plain old lens flare.
This almost never happens on my 10-22, so I tried the EW-83E hood that fits the 10-22 and 17-40 on the 24-105 and lo-and-behold, it fits perfectly.
So -- I'll be out today trying that hood on the 24-105 and will report back to the forum later. Just wanted to alert FMers to this option and maybe see your results if anyone else tries it.