I know on one of my rentals the depreciation will vary by $1 on some years. I attribute that to rounding. For example, I have depreciation of something like $3017 per year for the first say, 4 years. Then it year 5 it shows $3018. Then year's 6 -9 it shows $3017 again. This is easily attributable to rounding.
What really matters is the amount shown on the 4562 that prints in portrait format, as that is the one sent to the IRS. The 4562's that print in landscape format are not an "official" IRS document. They're just for your records and are never sent to the IRS.
Sounds to me like the math used for the portrait 4562 may not be using the same numbers as used for the other 4562's, or the math may be rounding for one, and not the other. But that's just a guess really.
