I have been using FF 3.6 for a while and have enjoyed the features and speed of this browser. I was particularly happy when Mozilla announced that a new browser would be released, given that new releases often bring new features and functionality, albeit with a required period of time to learn how to use them. I was disappointed, however, with FF 4 because of an issue with Blackboard Vista, which is the class portal used at my university. FF 3.6 worked well with this system, but FF 4 is unable to initialize the Java RTE when I try to upload files. Reinstallation of Java RTE did not help. Because I use this feature daily, I had to revert to FF 3.6. I would like to upgrade to FF4 in the future, but until this bug is fixed, I must stick to 3.6.