I had this problem. I spent quite a few hours weeding out my mods folder, and I ended up with some very odd results (to see weird testing details, please visit page 8 of Anach's Sims 3 Mods thread). The lack of ice cream (for my game) ended up being due to Anach's Ambrosia Group Serve mod. According to Anach, though, there are no conflicts, so I just chalk it up to a cosmic mystery.
I shall experiment with this theory!
EDIT: So after removing the AmbrosiaGroupServe mod, the ice cream promptly showed up! I found that I had some mod's in separate folders that apparently I missed when removing, haha. Still, I wonder what could be causing this, considering he says it's not a problem?