Re: The lens correction option in Lightroom 5 is for the Tamron 28-75mm lens, rather than the correct Tamron 18-270mm, even though it's correct in the Library metadata. How can I fix this?

I always shoot with the 18-240mm Tamron lens. The metadata are always correct. However, when I move to the Develop module, and check Enable Profile Corrections, sometimes it shows the 18-270 lens, but other times it shows the 28-75mm lens, no matter whether I choose default or Auto - and it won't let me change it.