Stymied by 4e module conversion

I just (mostly) finished preparing my first fourth edition D&D adventure. I had planned on doing a quick conversion of U1 The Sinister Secret of Saltmarsh, but was frustrated. I ran into enough things which were omitted or entirely changed in 4e (no more Charm Person spells? No more Illusionists?) that I eventually decided to create an entirely new adventure vaguely inspired by Saltmarsh. I'm running my Malevolent Mystery of Marshburg tomorrow, and will report on how it goes. If my players remember Saltmarsh, they'll be in for a surprise.

Anyone thinking of doing a quick conversion of an old module for 4e should be wary.