Assuming both were sold at a gain, it "sounds" like you didn't work through the "sale of assets/depreciation" section of the one that's missing from the 8582. Just a guess at this point, since I really don't have any other information to work with.
If on the 8582 you have numbers on both lines 3a and 3b, then you sold one at a loss and one at a gain. Need to know the facts, because if you did "in fact" sell one at a loss and the other at a gain, it's a bit tricky sometimes to get things entered correctly in the program. This is *extremely* important if one or more of the rental properties has more than one asset listed in the Sale of Assets/Depreciation section.
