To put it short, sometimes it just doesn't load at all.
I've just bought a 3in1 Expansion Pack yesterday.

All it does is show me this:

[/] 2 games
And a blank page.

And when you press any buttons, it doesn't do anything.

I have an R4 btw.

 

I use mine with an R4, I don't have any problems you seem to be complaining about. The R4 doesn't have built in support, you need a program to use it.

go read this first:
http://gbatemp.net/index.php?showtopic=130659

 

that one didn't work for me.

use v0.57.

 

The modes a color coded, the blue screen text is PSRAM mode, green screen text is NOR mode.

Switching between the modes you use the L and R buttons. It also tells you what mode your in at the bottom screen. Are you wasting our time?

It also tells you what the buttons do in a small window on the bottom screen. You must be wasting our time since you don't even bother to read whats on the screen.

The blank screen thing is more likely you didn't load anything to NOR mode first and tried to access the 3in1 with nothing on it.

 

then your buttons don't work. or you got a defective cart, get a new one if thats the case.