Okay, so I decided to load up Austerity as I was feeling nostalgic. :-)

I see my systray has a tendency to disappear now. If I recycle, it's back. Yes, I've searched the Themes forum and haven't found anything for systray - i found a reference to taskbar3 but I'd already updated that to use taskbar3-0.306_alpha-4 with no change. I can set "GripperIsClickable" to true in the themevars.rc to redraw the bar, but it gets rather tedious.

Hmm... seems to disappear whenever the taskbar is updated, either adding or removing icons. Looks like I'll have some 'splorin' to do...

Anyone else aware of an issue / problem?

Yes, I have also seen this. I have net seen why, but your not the only one. It is my favorite theme. Hopfully somebody knows a fix.