A few questions

[Lord Pendragon]

Ahem. A magic item, even a single-use item like a scroll or potion, is not a spell. Casting dispel magic on an item will suppress its properties for 1d4 rounds, but that's it.

I believe that Seule was talking about the effects of the potions being subject to Dispel Magic. In which case he's right. Although, as you say, the potions themselves (before being drunk,) can only be suppressed.