I was about to mention that ripple editing is on its way I believe.
that's a new feature and it should help with some of the problems seen here.
Don't knock all new features. Some have been huge time savers.

Base 57
   Apparently an inserted measure will always have the time signature of the preceding measure. So to insert a 3/4 measure after a 4/4 measure, insert using "ticks". Multiply "ticks per quarter note (found in preferences)" by the number of beats being inserted. For me this would be 2880 ticks (960X3). Then edit the time sig for the newly inserted beats to 3/4 and the following measure back to 4/4. Subsequent Time sigs should be correct if you use the slide option in the insert time dialog (I have no clue why you are getting that 27 measure slide; I can't replicate that).
  I believe all of us are hoping that 'Ripple Editing" will solve some of these arrangement issues.

Old thread, but thanks for this very helpful tip. My compositions use A LOT of time signature changes and since I use Sonar as a composition tool I mess a lot with them. One section might start as 5/4 and then later on change to 7/4 or whatever as the song evolves so this trick is very, very handy.