Assuming you haven't moved things around since installing perl5.6.1, the reason that Apache cannot find the libraries in the 5.6.1 directories is that the web server is running the perl5.6.0. If you actually manage to get perl5.6.0 to look in the 5.6.1 directories, you will then be running perl5.6.0 with the perl5.6.1 libraries, which seems like a bad idea. (If you built 5.6.1 and then moved the directories around, your perl installation will be all confused because the contents of @INC are compiled into the perl binary.)
I've thought of a few possible solutions:
- Rebuild Apache for the new installation of perl5.6.1, for which you have already installed the required modules. [*]
- Install the required modules in the perl5.6.0 CPAN shell again, but first upgrade the CPAN module so that it will not install a new version of perl itself unless you actually ask it to. (That misbehavior was finally (!) fixed.)
- Switch over to perl5.6.1 completely, and then rebuild Apache for 5.6.1.
You haven't given details about the problems you experienced when you upgraded to 5.6.1 previously, but I would like to point out that perl5.6.1 fixes many bugs from the 5.6.0 release; see the 5.6.1 perldelta for more details.
* I don't know a lot about Apache; I suppose it may be possible to get Apache running with perl5.6.1 instead of perl5.6.0 without rebuilding the web server.