transporters that can't lock on to moving people when Archer's first time being beamed up was when he was running...
The transporters in ENT were always much faster than the transporters in TOS. I always took that to mean that there was some additional aspect added to the transport process by the 23rd Century that made it slower: The bio-filters.
Think about it. Transporters in the 22nd Century would necessarily be more primitive, and the ability to detect and then filter out foreign organisms sounds like a much more complex process than just transporting whatever's there. So I figure, by the 23rd Century, they added bio-filters to the transporters, and that both slowed the process down and required the subjects to be relatively stationary (unless the transporter operator was really
good, as in the new movie).
I love this stuff.
Star Trek Fans: Explaining Away Production Goofs Since 1966.