Odd (and subtle) SNES issue

This concerns a PAL SNES, original model, with SuperCIC installed.

It works fine, no problems whatsoever, except one little thing. It has a habit of going black, briefly. This usually happens about 2 minutes after power on, but has also occurred after extended play-time. It lasts for a few seconds and then video is back. Sound is present all the time. The TV does not act as if it loses signal (i.e. this lcd tv will display a message window is you disconnect the source).
This only happens once without powering off the console. I have played for a couple hours several times and it would only happen once. I have only observed it with SD2SNES, as it is the only thing I use.
So I have considered the possibility that the issue is with supercic, but I guess that would prevent the game from working? Bad rgb cable? But the problem is too "regular" for that I think.

Any ideas? Caps going bad?

 

Did the snes worked fine before the cic install,also do regular snes games work fine.