I have just purchased and entered up the 2-disc release of 'Underworld' and 'Underworld Evolution' which has been available in Region 4 for some months now.

I found I was able to easily copy and paste the CAST details from the existing profiles for the original single disc releases, inserting headed dividers and 'append' for the second title details.

This did not prove possible for the CREW.  The details from the first title pasted up okay, then but the details from the second simply replaced those already inserted whether I used 'append' to paste or not or inserted 'a divider'.

In the end, I inserted a divider (which, of course brought up the Crew Positions) and manually entered the details

I am curious as to why I could copy and insert the cast details (using 'append' + a divider )but could not do this for  the crew details.

Or am I missing something? 

If you want two sets of CREW data the second set (and beyond) add a divider in front of the CREW data you want to copy.  You can then copy that section to another profile and it will carry the divider across and remain separate from the existing crew.