odd.. mixtures up the crap house possibly!??
what would be worth doing is getting a video of what is happening. obviously pictures wont work in this scenario.
If you cant really explain it better than you have, then a video really is the only way.
As an example, I had car problems, with a knock in a rear cylinder, I video taped it and posted it and was given over 30 resposes to what the likely cause was, and know what.. when I tore the engine down.. they were right!! Previouusly I explained my problem, as you have, and was suggested it was timing, a dodgy plug, a rock in the engine (WTF?), but once the video was up.. problem sorted within hours.
Its best to give as MUCH information as you possibly can. we are not phycic unfortunatly, nor do we know exactly what you are doing.
final word..
VIDEO..