Bug Tabs not notifying of new Shouts

Hey guys, back again with another issue... hoping this one will be easier than the last!

For the longest time, when users would switch to a non-default tab in the shoutbox and post a shout there, the tab would "light up" (change color), and other users could know there was someone talking there.

Starting a month or two ago, this suddenly stopped happening. Can still switch in and talk in different tabs, but for users in the default tab, they have no way of knowing the other tabs are ever being used.

Looking in the CSS files and StyleVars, I'm pretty sure nothing was changed that might have led to the color-change stop working there. I tried editing what I assumed would have been the tab-default color and the tab-alt and tab-highlight colors in dbtech-vbshout-colors.css from the StyleVar reference to hard-coded HTML, and nothing changed at all. Almost seemed like the stylesheet wasn't being parsed... I changed the shoutbox background colors in there to test it and they didn't change either.

Is there some sort of setting that I'm missing, or perhaps a CSS variable I'm not setting properly to get this working? I know other style templates and CSS are being written to on my server and working properly, so I know it's not an issue there.

The relevant CSS class is vBulletin-defined and it's the "highlight" CSS class - ensure there's a background-color attribute to that CSS class.

I'm not seeing the tabs light up despite having the highlight color set. Any ideas?

Have you customised any vBShout CSS templates? If so, try reverting the customisations.

No, it is a stock install.

I believe the problem was with the aop directory not being set. It wasn't apparent that there was an issue until I saw a lot of 404 errors for the txt files.