Game Not Loading

I downloaded, extracted it and placed it in the 'games' part of r4 card. However, the problem happens when you try to load the game. Nothing shows up but a white screen. What am I doing wrong? Bare in mind I have never done this before.
Post Merge: [time]1341346925[/time]
More information: Other games that were downloaded in 2009, work on it yet the games I have downloaded from this site, do not. I need help ASAP please and thanks in advance.

We need some more information before we can help you.What R4 do you have specifically?
Is it running the latest firmware?
What is the cards website?
What ROMs are you trying to play?
Have the ROMs been patched?

This issue is quite common, you've got to change some settings to make it work. the first is Cheats: should be global off and reset in game to. Show icon should be transparent. After you've done this than it should work. Enjoy !