I'm not sure if it's a bug or a matter of configuration. When I use perl5db.pl as a perl-shell and any error occurs, some special variables and settings get lost. This error is not reproducible with V1.3, but this belongs to Perl 5.10 and I'm not sure if I can safely install this version in conjunction with Perl 5.8.8.
Here an example:
lanx@xubuntu:~$ perl -de0
Loading DB routines from perl5db.pl version 1.28
Editor support available.
Enter h or `h h' for help, or `man perldebug' for more help.
DB<3> print 5/0
Illegal division by zero at (eval 12)[/usr/share/perl/5.8/perl5db.pl:6
+28] line 2.
at (eval 12)[/usr/share/perl/5.8/perl5db.pl:628] line 2
eval '($@, $!, $^E, $,, $/, $\\, $^W) = @saved;package main; $^D =
+ $^D | $DB::db_stop;
;' called at /usr/share/perl/5.8/perl5db.pl line 628
DB::eval called at /usr/share/perl/5.8/perl5db.pl line 3410
DB::DB called at -e line 1