All things Spider can be found at www.dxcluster.org and the actual program and patches can be found in the download area.
Patching is done in the standard linux way ...
zcat /tmp/patch-1.40 | patch -p0
assuming the patch version you are using is 1.40 and resides in /tmp!
Be aware that each patch assumes the previous patch has been applied. That is to say if you are patching from version 1.38 to 1.40 you would first need to apply patch-1.39 and then patch-1.40.
The tarballs are designed to not overwrite your existing configuration and can be used at any time to update your Spider software. All the key files have the suffix .issue (eg. DXVars.pm.issue) at default.
The version of Perl that comes with 5.2 seems to be some kind of pre-release and is broken. You can get a new version of perl from www.dxcluster.org or ftp://updates.redhat.com. Don't forget to patch it with the CPAN modules.