I'm sure there have been, because anytime there's an iOS update, there are plenty of people that run into errors, usually caused unintentionally by the user.
Make a backup of your iPhone first, and then update if you choose to. I recommend updating via iTunes & USB, not via wi-fi, personally.
well yesterday after the phone alert me about a new update my wifi stop working, the phone stopped looking for any wifi network...so i decided to restart and nothing....them I upgraded to 7.0.6 and now the wifi option is in grey...I cannot slide...so there you go...new update new problem...
My phone is an 4s