"The KISS principle (acronym for "Keep It Simple, Stupid") states that design simplicity should be a key goal and unnecessary complexity avoided." (WIKIPEDIA).
The new feature to insert media is very nice - if it works.
At home, with my own computer, it works.
At work, part of a local-area-network, it doesn't work!
Probably, this isn't a mistake in WP2.5.1, probably there is something wrong with our network, but this is the reason why I ask you to follow the KISS-principle. The probability that everything works fine on every platform, rises with simplicity!