Currently, with SL Viewer v1.19, if you set Preferences to open web pages with internal browser, it will… surprise, surprise… actually open with the internal browser!
But with 1.20, it opens with the external browser! This has been reported since RC5, but yet the Lindens say that 1.20 RC6 will probably be the last iteration before general release. Not good.
Why is it important? Because many of the help and information pages in the Lulu Signature line are connected live to the internet, and frankly, it’s more than a little annoying to be thrown out of Second Life into Firefox / Explorer / Safari / Opera on the desktop.
Please vote to fix this… here. You will need to login on the left hand side (don’t worry, this is an official Linden website), and then you can vote.