You may have 2 separate issues.
PS2 – is it set to RGB output? Also, the csync cable web page notes that it has a sync cleaner built in. The general rule is to not use a sync cleaner with the OSSC. However, the webpage says it is compatible with OSSC. Maybe someone else can chime in on that.
Wii – have you tried changing ‘480p in sampler’ (under <sampling opt>)? I have mine set to DTV 480p. I frankly am not certain that is the best for the wii, but it works. I believe I did some research and adjusted settings to be correct for what the wii outputs, but don’t remember for certain. What I’m trying to say is, these settings work for me, but don’t take them to be the absolute best optimization.
That said, below is what I also have for <sampling opt> -> 480p timing (this probably needs to be 576p timing for PAL)?
H. Samplerate – 858
H. Synclen – 62
H. Backporch – 58
H. Active – 720
V. Synclen – 6
V. Backporch – 30
V. Active – 480 (this probably has to be 576 for PAL?)
And lastly, <sampling opt> -> sampling phase – 180 degrees
Also, <sampling opt> -> ‘Allow upsample 2x’ is a nice feature to turn on, in my opinion, but won’t have any effect on your blackout issues.
Then again, this may be completely unhelpful due to NTSC vs. PAL, but hopefully it helps.