HELP! I can't install anything! :(

[kuso]

Okay, i've been trying to install a camcorder app. I've tried ETI and the Phillips one, but neither would install! I don't know why. I open them from the MMC card in FExplorer, and it saves to installer, but nothing else happens from there. I go to the installer and next to the filename it has a little cube. I go to options -> install, a progress bar shows up quickly and then nothing!

I'm using a Nokia 6600, btw.

Please help!

Thanks :)