Sorry, basically your reflex is equal to the greater of dex and int plus 10. If you're wearing light armor, you add that reflex bonus to your armor and shield bonuses for your AC. If you're using heavy armor Your Reflex bonus to Armor class is effectivly 0.
Okay, so while talking with Jonas last night, I've found the following passage in PH1 on page 212 of the book (which might be slightly offset from the PDF page number in whatever copy you use):
When you wear light armor, you add either your Intelligence or your Dexterity modifier to your Armor Class, whichever is higher. Heavy armor is more restrictive, so your natural agility matters less. When you wear heavy armor, you don’t add an ability score modifier to your AC.
Is that what you mean? There's also Reflex Defense, that gets an Int or Dex (whichever's larger) bonus to the base value... but the PH doesn't mention any cases when this bonus is canceled. Yes, same page 212 says
If you wear armor you’re not proficient with, it makes you clumsy and uncoordinated: You take a –2 penalty to attack rolls and to your Reflex defense.
But that's a different thing altogether.
Also Tvor, why no shield? I understand it if you were using a two handed weapon, but one handed it just seems kinda wierd.
Honestly? I don't like shields... and I can't imagine fighting with one.
;
In any case, it's not a total waste (just an almost-total one), as the hammer can be used in two hands for a (lousy) +1 damage bonus.