R4 Troubles/Question

I'm new with my R4, and i have a problem.

I cannot get the action replay to work at all, the games always freeze up at a white screen before they start.

As for the question, what does the red R button in the corner of the screen used for?

Almost forgot, it's a R4HC, its got an updated Kernel, and Ive dldi patched what needs to be patched.

huh...not so familiar with r4 sdhc

The red R button indicates soft reset is off.Green is on.To activate when a game has been loaded, press L+R +X+Y+A+B all at the same time.