Originally Posted by DiapDealer
I get the exact same results you do. With Calibre 0.8.20 and 0.8.21. The mobiperl tools (or more specifically, the Palm/PDB.pm perl library) expects the Palm Database Name to be terminated with a null character otherwise you get the error you're getting:
# database names must include a terminating NUL.
die "bogus database name! is this really a PalmOS file?" unless $name =~ /.+\0/;
So maybe there are certain conditions in calibre conversions that result in a Palm Db Name that isn't null terminated when long titles are involved? Somewhere between 52 and 56 characters?
Is the null termination an official specification of the file type? Because if it is then it's a bug in Calibre...