Yes, that is what TurboTax is doing. It is probably correct.
TurboTax uses the Mathematical Method of depreciation, rather than using the Depreciation Tables. Using the Mathematical Method, it gradually 'pays back' the incorrect prior depreciation that was too high. A similar result happens when there is a change is in percentage of business use.
I say that it is "probably" correct because once you start using the Depreciation Tables, you are supposed to keep using them, and not switch to the Mathematical way. I would strongly guess that most software uses the Mathematical Method. However, generally nobody really knows what method they started using, so the IRS probably won't raise a fuss over using the Mathematical Method.
Personally, I would just leave it the way TurboTax is doing it. If you do want to override, you need to use the CD/downloaded version of TurboTax. You can not override with the Online version.
