Weird that they differ. The 'perl -V' output is derived from $summary in Config_heavy.pl (so you could hard code in the correct value there if you wanted), but I couldn't find where $version_patchlevel_string is set. The bug may not be of great consequence, but should probably be reported to ActiveState.
It would be a good idea to check that both $^V and $] report v5.10.1 and
5.010001 (resp).