Hello there!
I had some problems with Procaster not working on my laptop due to an underpowered system, so I was suggested by the Livestream Support to use Adobe's Flash Media Live Encoder. I managed to download it and studied the guide page here about using it with Livestream:
http://www.livestream.com/userguide/...ith_Livestream
However, after I installed, I noticed that it could only be used with a Webcam, to record live footage, and not your computer's desktop, which is what I'm interested on. Then I went to search on the internet for some sort of solution for that, and found a GREAT guide that explains step-by-step how record and stream your desktop screen with FMLE and a couple of other programs

And I thought I would share it here with others, as I found it very useful. Here's the article:
http://root-destiny.com/newbies-guide-to-streaming/
The link for VH Screen Capture 2.2.8 in the guide appears to be broken, and I had a hard time searching for it on the internet, but I managed to find and download mine from
Cnet. Their version is 2.2.2, but it's practically the same thing settings-wise than the guide's version. I have already tested it, following those steps, and it all worked fine!
So, I hope I could help anyone here who had the same doubts/trouble with desktop streaming using FMLE as I did!