SlideIn Plugin isn't working properly

I have created 2 slidein messages.
One has to appear from the left only if the user is not logged in and after having scrolled 1% of the Homepage.
The second slidein message should show after 1 second and from the bottom and anyone can see it.

Aside the fact that in IE probably the z-index is not set properly and the youtube videos overlap the slidein message, what really I cannot understand is why they don't show always when the correct circumstances occur (meaning: not logged in, having scrolled 1% of the Homepage and 1 second has elapsed).

I hope I was clear enough for you to understand my problem.
Thank you for you support and I wish you a Merry Christmas!