From this KB article,
In Microsoft Access versions 7.0 and 97, the DAO 2.5/3.0 and DAO 2.5/3.5
compatibility type libraries were included. These libraries were used by default
for converted Access 2.0 databases, and therefore still allowed the older legacy
code originating from Access version 1.0 to work in Access versions 7.0 and 97.
Microsoft Access 2000, however, has no compatibility type libraries, and
therefore, DAO code that uses some of the older syntax may not run.