Like tc, I'm a TNIV fan, but like him (after reading his post, at least), I'm puzzled and unconvinced by Fee and Stuart's argument for translating "peripateo" as "live" instead of "walk" in 2 Cor. 5:7 ("for we walk by faith, not by sight," NRSV). (It looks to me like the problem--or issue, at least--arose with the NIV, so it's not a TNIV-specific matter.)
Read all about it at tc's post--including the comment citing O'Brien on Hebraistic influence.
By the way, the NIV also took "walk" out of passages such as Romans 6:4 ("walk in the newness of life," NRSV), Gal 5:16 ("walk by the Spirit," RSV, and Eph. 2:10 ("that we should walk in them," RSV)--though the NRSV, my default translation, followed the NIV on the latter two moves. (tc now notes that the TNIV actually put "walk" back into Eph 5:2!)
διὰ πίστεως γὰρ περιπατοῦμεν οὐ διὰ εἴδους
dia pisteōs gar peripatoumen ou dia eidous
per fidem enim ambulamus, et non per speciem
for we walken bi feith, and not bi cleer siyt.