The gentleman teaching me pronounced the 'h'. As in 'ka-hə-dek-san' and 'u-hə-dek-san'.

Perhaps he was trying to emphasize that the 'h' must not be left silent. There's no vowel implied after the 'h', though.

Dialect differences rear their heads. For a fun read on one major class of Finnish dialects, check out http://en.wikipedia.org/wiki/Savonian_dialects

If I were good I'd be able to identify the region of Finland your teacher came from. Someone from Finland, help me out! Is that a Savolainen murre?

Nope. Though "kahareksan" sounds like something you'd hear in Pohjanmaa.

Yeah it's the dialect of my hometown - that's def not standard Finnish :)