>thing I changed was the Target and Max bit rate
I don't do BluRay, but you MAY have exported out of PPro into a file that is not "legal" for a BluRay
The below saved links may help explain...
Premiere Export Formats
FAQ on "best" settings http://forums.adobe.com/thread/878590?tstart=0
http://help.adobe.com/en_US/mediaencoder/cs/using/WS725e431141e7ba651e 63e3d1267818bc51-8000.html
Encore Files & Formats http://forums.adobe.com/message/1901666
http://help.adobe.com/en_US/encore/cs/using/WS5C9E1CF8-B5BC-436f-89D3- 61DDC02A2C47a.html
-and http://forums.adobe.com/thread/622722