Kev999
Try this (an alternative approach).
1. Jot down where you want to insert the measures. Let's say it's at measure 41 and you want to insert 8 measures there.
2. Select All (control A)
3. Under the Edit menu choose Select By Time
4. Put in start time of 41 1
5. Put in end time way later, like 150 1
6. Cut Special (control alt x). Choose to include the markers if you have any.
7. Paste special (control alt v). Paste starting at 49 1. Choose to include markers if you have any.
That will also insert the 8 measures, and eliminate your audio clip issue.