Something is really wrong here. This should not be an issue. Your drummers tracks (if recorded and sent to you properly) absolutely should import and line up with your session. A ProToosl Mix+ can import and export SDII , AIFF and wave files to and from each other at 16bit/44.1,16bit/48, 24bit/44.1 & 24bit/48.
Somebody somewhere made a mistake.