Im the DM so I know my word is law but I had an Artificer place the Landing ability (Magical Item Compendium Pg. 12) allowing for "ignoring the damage from the First Fall of 60'"...but the armor Infusion lasts 100 minutes. Now I think that after a single fall the spell is used and thats that but of course he thinks that its every fall for the next 100 minutes. I laugh now that I think who could fall more than one per round...ok nevermind then, LOL
To clarify is he saying that unless the fall is "60" then the power is still active, so would try to jump down a mountain 50ft at a time? :D Personally I'd say it ignores your first fall "up to 60" for 100 minutes. Whether you choose to nullify it after a single fall (even if it is 10ft, which is quite harsh) or give it 60ft of fall damage DR for 100 minutes, so the spell can absorb a finite amount of damage either cumulative or from one 60ft drop.
The way he wants to use it I don't think is in the spirit of how the spell is intended.