When these 16bit clients do a server directory listing from a command prompt, or an application searchs for its DLLs on the server, an SMB 81 (Server Message Block 81) is used to get the directory search. The cause of the problem is that the filenames from this SMB will be intermittently truncated.
To resolve the problem, use Regedt32 to navigate to:
Edit or Add Value name MaxGlobalOpenSearch, a type REG_DWORD entry. In the DWORD Editor, select the Decimal Radix, and enter a larger number. The default is 4096. The minimum is 1 and the maximum is 65536. I recommend trying 16384.