need to tell my computer to trust a certificate

[lacyb]

I accidentally told my computer not to trust the app that adds photos to my FAce Book page. How do I get it to trust it again?

[rundie]

Is the app a browser extension of some kind? sounds like you need to trash some preferences/cookies...

[ilaureano]

The FaceBook photo add app is a Java applet, as it takes the photo files from the hard disk, it needs permition, so the computer needs to trust it. In my case, the browser asks every time I try to upload photos. rundie is right. Try to delete the cookies and cache in your browser preferences panel.
In the control menu for the browser (guess you use Safari, I prefer Firefox/Camino), the "Control menu" is the menu which has the browser name, next to the Apple menu, the shortcut key for the Prefernces panel is is Command+,
In the tabs Privacy/Security/Advanced are the control and configuration buttons for cookies, historial (controls the cache) and certifications (controls wether the computer trust an app, refuses the acces or asks everytime).