Most likely what happened is that you didn't restart the LeanFT engine after enabling the browser agent. You want to treat the opening order similar to that of UFT. Make sure that you start LeanFT first and that the LeanFT is started and active (it can sometimes take a minute for it to be fully active, I've noticed). Once that is done, then you can start your browser.
I have noticed a quirk using with web object identification while I'm using Eclipse, but haven't tested it yet fully to see what's causing it. If I open IE after LeanFT is open and active, I am able to see web objects. If I launch the browser programmatically with LeanFT, after it executes, I can no longer identify web objects. I'm waiting to hear back from HP as to if this is by design or a bug.