In 1977. when Charles Widmore was talking with Eloise over the dead body of Daniel, Richard Alpert went to Jack and Kate to untie them. Then strange thing happened:

Jack asked Richard who was that man reffering to Charles Widmore.
Then Richard replied:

"That man, JACK, is Charles Widmore!!!

How, in the hell, Richard knew Jack's name? They never met before that and he couldn't have known his name anyway! He saw Kate previously with Sawyer when they handed him Ben to be healed.

Another error or am I not paying attention.

Any thoughts?

I haven't gone back and checked, but weren't Jack and Kate wearing Dharma jumpsuits? I think their names were on them.
100%
Just checked Follow the Leader on Hulu. Here's a pic - you can definitely see Jack written on the jacket.

http://img130.imageshack.us/img130/7384/jackdharmasuit.png