Changing timing of subtitle slates.

First off, great product.  Just did my first video and it worked great.  Had to edit a few words (to be expected).  Very smooth, very fast process to get subtitles and have them look great.
Here is the one challenge I found…
The software does not always get it right in terms of where on the timeline we need subtitles and when we need blanks.  Is there any way to insert new blanks or change the time of a subtitle slate?