Afflicted/Gladiminish/SA random disfunction

[Actually]

Hey there,

I'm actually havin' some problems with my Interface.

There are some important arena addons (listed in the title), which for me sometimes work and sometimes don't.

But from the top, example Gladiminish:

I logg in, go for some skirmishes and am glad to see my enemies diminishs. But after a few skirmishes (lets say an hour?), I don't see any diminishs no more.
There is no error popping up or something.

So, after a few days I decided to delete my Interface and my WTF folder, used a few hours to get my interface back working and then hoped the problem would be solved. But it isn't.

If I relogg, the Addons seem to work again. Sure, no big problem as I'm not playing any rated games right now, but with the start of the new season it would suck if I'd have to go like "woops, interface..." in an important game.

Since I deleted the folders, I haven't copied afflicted and spell alerter in my wow-folder, but since the gladiminish problem persists, I think those will make trouble, too.

Anyone got an idea? What could be the issue?

I'd be grateful for your help.