crowtrobot313, great question - and this is one place where tablature does NOT always provide us all the information we need - like, how long a note should last within a measure, etc. 

One option would be for you to see if you can find a standard-notation version of the song you are working on, and use the note-values represented in the measures that correspond to the the TAB version you are using, to see if you can de-code the timing.

Another option is to see if you can find a recording of the piece to listen to - slow it down if necessary, and see if you can actually HEAR how the timing is supposed to play out in those mystery-measures.

Hope this helps a little!

-Lisa