I have not used the Friends option yet. If you're sure that the advanced window for both of you say you're not behind a firewall (which does not necessarily mean you cannot connect), then I'm not sure what the problem might be. My only thought might be something to do with Vista's security, the permissions on his folder where his files for share with Friends is.
However, Browse host has never been a perfect tool, it is supposed to have improved greatly for LW 5 compared to LW 4. My impression was it had improved. Friends is more or less the replacement for Direct Connect option of LW 4.
No simple answers at this point. One alternative, at least for time being is using magnet links. He creates a magnet link to one of his files, sends it to you via email, you copy-paste the magnet link address into your browser & LW starts to download it. Then you Browse him using the
View Files of ... option by right-clicking the downloading file. If still cannot browse him. hmm ... something is interfering. ISP inbetween, it's hard to say. Perhaps even a less than great performing ultrapeer between you two.
Magnet links: Posts #3-6 here
http://www.gnutellaforums.com/limewi...tml#post339645 * BTW I do notice in your image, it shows a Medium quality connection only. This could 'definitely' affect things. If it's because LW was left alone for a long time, then waking it might set it back to full connection.
(Good to see you share a lot of files.

I share 2.5 times that but that's with LW 4, it seems for MacOSX, LW 5 does not like too many shares with this release at least.)