EDIT : Nevermind, I found the problem: the Lux app was blocking the install for God knows why. I'm leaving this edit so anyone with the same problem can find an answer...
I'm desperate! I rooted my TF101 B50 with ViperMOD 4.5, everything went fine, I have root access (installed Rom Manager, did a Titanium Backup). I am now trying to install RecoveryInstaller, and when I browse and click on the APK (whether on the internal memory or on a SD card), the popup that appears (cancel/install) won't let me install. I can click on cancel, but nothing happens when I click on Install (I don't even have the blue glow).
Of course, I have allowed the non-market apps.
What can I do?