First off, the majority of people with an issue here are generating a password in the Lastpass dropdown and then relying on the extension to paste it into the correct place in the registration password field to save. Considering the vast nature of the web, coupled with the fact that it changes as often as it does (and even more so in regards to login authentication/security), leads me to think we are asking a lot of the extension to perform flawlessly for all users when it comes to detecting which fields need the password placed into them.
However, when it comes to overall useability, online and off, mobile and desktop, there are no competitors of note, IMO. I hate LogMeIn and what they did to that platform and was scared to death when they took over LP. However, so far they have done nothing but improve the application IMO.
If you want a foolproof work-around that will solve all of your issues, stop using the "Use Password" function altogether and manually copy/paste the password of your choice into the accurate fields on the registration page. If you'll do this one thing, and it'll take less than 20 extra seconds, your chances of a successful Lastpass record being automatically scraped and created by the extension will skyrocket.
Note a key to my method is a free (I'm pretty sure it is open source) utility called Ditto clipboard manager
, as I have for years and cannot imagine my workflow without it. It saves the last n # of copied values in a dropdown menu in the systray and runs with very little overhead. That way you can always go back and see the last 10 things you have pasted which will generally solve any issues you have with the generator not picking up your logins. This has been my process for over a year now and I can say it has relieved any issues I have experienced with LP. Hope this helps.