The various options have been set up as individual lines (pressing Enter after each option)

If you tick "Make Poll Only", users cannot reply. Otherwise, it works like a normal post plus a poll, i.e. users can also discuss it.
If the user clicks "view poll only (null vote)", they can only see the results but cannot vote themselves.
Voting later isn’t possible – only members can vote (otherwise a guest could skew the results by clicking repeatedly).
I’ll have a look through the “language set” tonight. Hopefully the poll script will be in German by tomorrow... <_<
Mirko