Un-craftable Daylight Sensors?

[SpikeyThorn]

Well then, since daylight sensors where added in 1.5, i thought i'd make one, i didn't honestly think i'd have such problems...
The wiki says this is the recipie:

and sure enough, it doesn't work...

[Chipaton]

I cant remember where I saw this, but are those slabs old? Try making new slabs and using those.

[SpikeyThorn]

Yeah, that was it, cheers, kinda strange to think i've had those slabs since like 1.0... :p