I'm currently using Bartender4 (up tp date) and I've started making use of paging, as well as combat visibility options.
My custom conditions are, for Bar 1 and Bar 2:
State Configurations: [overridebar][possessbar][shapeshift]possess;[mod:shift]3;[bar:2]2;[bar:3]3;[bar:4]4;[bar:5]5;[bar:6]6;0
Further options: Fade Out at 20% alpha, 0 sec Fade Out Delay, Mouse-Over Casting
When I first start WoW, everything will work normally. But after a while, visibility of bars won't react to the combat trigger anymore, while the paging is deactivated during combat. Meaning, I can mouse-over and the visibility will trigger properly (even in combat), but the [combat]show;fade condition isn't doing anything. On the other hand, out of combat I can hold shift to page both bars to their second pages, but in combat, either or both bars stop being pageable for some reason.
I use Bug Swatter, but I don't seem to be getting any errors about Bartender4, or they aren't getting logged.
Please tell me if you need more information from me.
Edit: I've been able to determine that very likely the addon CompactRaid is not compatible with Bartender4. Most likely the affecting part of CompactRaid is the "clique" equivalent. I've turned that addon off completely for the moment, but when I need it I'll try again.