Problem with Super Mario World - SNES

Hello, I have a problem while playing with Super Mario World on a PAL Super Nintendo.
After some googling, I see someone had the same bug :
http://www.gamefaqs.com/boards/519824-super-mario-world/41090798

The problem come from the console, almost no doubt. The same console has a blinking problem on Mario Kart but this one uses a special DSP, so I guess it's not the same problem in Super Mario World.
What could explain the bug, where Mario can't stand on a moving element ?
I will try to open the console soon, but I would like to have your advices.

 

Do you have street fighter 2 turbo to test? I'm curious if this could be related to the lock out chip. I have a SNES console that acts up like this on certain games, too. But the same game on another SNES works perfect.

 

I don't have street fighter 2 right now but I will try to find it. A non "turbo" version would be fine for the test ? What could I notice in game please ?

 

is it a pal version of super mario world? ntsc on pal consoles causes crazy timing issues.

 

It is the pal game on a pal console.