Yea, that's the issue...change that value to #777 and you'll be good. After doing that, call yourself and you should be able to answer the call fine. A note, this will not shut down your data connection after a minute or whatever, but that shouldn't have an adverse impact on your battery...just an FYI. If you go into Adv Config or whatever to reset data off after a certain time, it will reset THIS reg edit and your call answering woes will return.

...and now you know. ...and knowing is, you know, half the battle.