The settings take effect immediately when you hit the "Update" button. The info is stored to the database and is fetched directly from the database each time a page is read in case you changed a setting.
However, it's possible that settings are getting cached by the local browser. I always set my browser to check for changes in a page each time it loads. If you've got a broadband connection, you can actually disable caching completely, but it does generate a bit of a load on websites like this one.
I've got an easy-to-find variable in the Favorites routine that I told Matt to adjust if he saw utilization go too high. It's a number of seconds to add to everyone's refresh rate to reduce the number of automated hits to the Favorites page, which is still a pretty expensive one as I haven't done the heavy-load tweaking to it yet.
Doug, I'm not sure if you're right or wrong, but here's the situation with those first two options.
The first option toggles auto-refresh on and off. Has nothing to do with whether or not the contents of the favorites page will change each time you go to it. It's dynamic and is put together from the database every time it's used. As such, the first two options go hand in hand. If you've got it set to Off (False), the second option become meaningless.
A good way to test to see if caching is a problem is to make sure the date/time display for Favorites is enabled on the same screen. If it is, but the timestamp isn't changing on each reload or automatic refresh of the Favorites page, your browser is caching too aggressively.
Regarding the Investors Hub window grabbing the focus (if you're in another browser window) or flashing in the taskbar if you've got another program running in the foreground, whether you see a difference in your MailBox number will depend on what you've got in "Alert Browser Window On New Messages".
If it's set to "On", that's the most aggressive setting. It'll focus on the iHub window anytime there's a new message in any of your Favorites boards. If you have it set to Off (which I think is the default), Auto-Refresh will still work, but the iHub window won't grab the focus. If you have it set (as I do) to "Message To Me Only", the focus-grab will only happen if your MailBox count has changed since the last time Favorites loaded; not when new posts are written on Favorites boards.
For those who don't know "grabbing the focus" is just geek-speak for "Making the iHub window the currently-active one on the screen."
