From Tax Prof blog:
Tax Court Rejects Geithner/Turbo Tax Defense
Bartlett v. Commissioner, T.C. Memo. 2012-254 (Sept. 4, 2012):
Petitioner admits that her income was misreported and that her taxable income was underreported. She maintains that she reported all of her income and that the mistakes made were “honest mistakes” resulting from her lack of familiarity with the TurboTax program. Petitioner claims she used the audit portion of the TurboTax program, believing the audit portion would catch any mistakes she otherwise might make. …
It is apparent that a portion of the information petitioner entered into the TurboTax program was incorrect; hence the mistakes made (which resulted in the underpayment) were made by petitioner, not TurboTax. TurboTax is only as good as the information entered into its software program. See Bunney v. Commissioner, 114 T.C. 259, 267 (2000). Simply put: garbage in, garbage out.
You can find a history of links to posts on the issue at Tax Prof.