The virus checker Thunderbyte Anti-Virus is known to be triggered by the programs MSODBALL.COM and FBSTRIP.COM. It is also extremely puzzled by CP/M .COM files (and COMMAND.COM under DRDOS 6).
If no programs other than these trigger warnings, it is very likely that they are false alarms. Unfortunately, the method used to make the programs run under CP/M or DOS looks similar to the methods some viruses use, and the CP/M data in the programs, being incomprehensible to the checker, arouses its worst suspicions.
Despite what the TBAV documentation says, these programs are not badly written (well, not very...).
It is possible that similar warnings may be given by other anti-virus programs.
Some versions of Norton Anti-Virus also give a "Bloodhound.boot" warning on MSODBALL discs. If these are updated with the latest virus definitions, they should be OK; if updating doesn't work, let me know.
DualDOS discs cannot be read under some versions of Novell DOS 7 or OpenDOS 7.01. The solution is to apply Novell update 15/2, or (better) upgrade to OpenDOS 7.02.
Windows 95 should not be allowed to write to a DualDOS disc; this makes it unusable by CP/M computers. The best solution is to write-protect the disc; failing that, run the .REG file below to stop it altering these discs.