Enhancements to the standard IBM Lotus Notes 6.5/7.0/8.x mail template.
Have also encountered this bug. This is not an issue with multiple addresses nor with the OrderNum field. Removing the 'Rules' script library and replacing it with the library from the Notes 6.5.3 template fixes this (although other things are undoubtably broken now – what exactly we haven't found yet). But this functionality was critical so we implemented the fix as described.
Congrats on the new release! This problem appears to be fixed in 1.5. Thanks!