Thanks for posting this.
I've been tearing my hair out looking for a solution. I was about to download Chrome.
Not much point having a help button on Sonar if the page won't open.
Removed all cookies as you said and the problem went away.
Cheers

FYI, there are three different ways to access Cakewalk help. The web based help is the default when connected to the internet, a local help file in chm format and a pdf version.
 
To force local help when connected to the internet check "Always Use Offline Help" in Preferences > File Advanced. The Advanced options are visible when the Advanced radio button is selected at the bottom of the Preferences dialog.
 
The pdf version aka the SONAR X3 Reference Guide is available for download here http://www.cakewalk.com/S...and-Quick-Start-Guides

Bajan Blue
You can use Firefox but it is very lumpy.
I use Chrome (just for Sonar Forum Basically) and it works fantastically well.  I would forget using Firefox for the forum...

For me it's the opposite. With Chrome I can only view the forum but not log in, whereas Firefox works ok.

Maybe things have changed since January 2012. This is not a new thread.

I'm forced to use Firefox at work and it works just as well as Chrome does at home.

Strike my last answer!
It was still causing me problems I had to clear the cookies and restart Firefox every time I need the Cakewalk site.
Chrome is now installed. So far, so good!