Are you sure you used the right rooting app for your variant of your phone? Installing the wrong one could kind of mess things up (since it installs a file to the system area).
As belodion said, join the Android Central community (so you can keep your answers in this conversation), and post your make and model of phone and a link to what you used to root it. (You can't post actual links, so put spaces in where the dots are - we know how to figure it out.)