Help with hefeweissbier

[carniebrew]

I've just developed (in the last 10 min) a theory as to what's going on. Everyone says to ferment these at about 17 C, but how are they measuring the temp? A lot of people have their probes stuck to the side of the fermenter with some insulation over the top. Wyeast 3068 ferments like crazy though, so maybe even with the insulation the beer temp is actually a few degrees warmer. I have my probe in the beer. Maybe I just need to ferment warmer (like my experiment is).

Could be onto something there, certainly all my recent successes with 3068 have been at 17C with my stc-1000 probe stuck to the side of the fermenter, under a piece of stubby holder.