I have seen 'however' used as a conjunction (like 'but') and to me this looks wrong. Can anyone confirm this?

eg: I went to bed, however, I could not sleep.

Surely this is not acceptable usage?

I am with you on this one. This subject is debated widely across many of the grammar chat forums. I 'correct' this all the time when proof reading.

In my view:

However, (< 95% of them should read like this)
; however, (< 5% can look like this)

, however, (you should only see this when it means 'on the other hand')

e.g. John, however, can drink like a fish.

I have considered making a banner stating 'However is not a conjunction.' and parading around London.

'Fathers against lower-case h's on However.'

(Someone would no doubt bleat about the apostrophe in h's.)

Right, I'm waffling now. I'm off.