Hi,
Just retested this on a x64 centOS 5.9 machine.
The help function works there. After selecting help from within Workstation it will indeed open a browser with the page.
However I have a suggestion. If the user is using a javascript blocker such as noscript then the browser window comes up completely blank/white. There's no suggestion that you have to enable scripting in order to get to see anything. A single sentence with "Please enable scripting" would help. I wondered for a few seconds why it wasn't working 
until I realized that noscript was being too helpful.
--
Wil