It was my thread you picked up.
I have been using LastPass since that date with no major problem at all, it's just like Roboform and has the same little glitches.
Some sites change the information they want when you log in, for example the log in may have been set up asking for your e-mail address and the password you generated and this is what is stored.
Then when you go in to that site again it may then ask for user name and password so unless your user name is your e=mail address it will fill it in incorrectly.
You just need to manually put in what they are actually asking for and LastPass will update it.
You can see what is stored in the Vault.
Alternatively your last resort is to go the forgot password route and set it up again.