This Baloney comes from a site which has a number of good answers, but which really slipped up on this question.
The key passage in this answer is:
"When you have salty water, the salts in the water make the molar
heat of fusion, (and the melting point) lower, and this means that
the ice inside this salted water will melt only at a lower temperature. And the ice cubes will melt slowly..."
Of course the explanation given is for why salt makes it easier
for ice to melt, lowering
the melting point. The person had observed the opposite effect.
We've got several answers explaining the physics of why under common conditions ice cubes melt more slowly in salt water even though it lowers their melting point. Here's one: http://van.physics.illinois.edu/qa/listing.php?id=1662
(published on 02/08/11)