I posted the same question in Adobe forums and waiting for reply from them also, but so far here are my results
I am using the old Surcode DTS encoder. .cpt and .dts files are fine for the dvd build but for BluRay I get message that audio is not valid.
I asked my friend overseas to send me some sample of his DTS Master Audio Suite encodes.
1) .cpt files using as DTS MAS for DVD DTS digital surround are working ok for dvd builds, for BluRay Encore CS5 just crashes when trying to build
2) .dtshd files using DTS MAS as Bluray disc DTS digital surround (not High resolution or master audio) are not accepted at all in Encore getting an info message that it is not supported in this version. Tried renaming thos .dtshd files to .cpt or .dts but I get codec error in Encore.