Turns out there are two old Infocom games that currently share the same IFID:
zork1-r5-sXXXXXX.z1 (listed here) both use IFID
ZCODE-5-------. This causes some problems, in particular in Spatterlight which uses IFIDs generated by Babel to tell games apart.
The obvious solution is to detect this particular version of Suspended (or Zork I) and give it a different IFID. But it would be nice if we all could agree on what this new IFID should be.