Parental Controls blocking dropbox connecting to the server

System:

2Ghz Macbook, Mac OS X V. 10.6.8

On the user which I use for work I am trying to block facebook and twitter via the parental controls web options. I have done this, however this has resulted in

my Dropbox (www.dropbox.com) not being able to connect to the server and therefore not being able to update or access certain files that I need to work on.

Is there any way around this?

Many thanks to any replies.