As noted above, you didn't give much detail so it's hard to give good advice. Three basic things come to mind. One: you can't generally install just one part of BioPerl in isolation -- you have to install the entire suite because of all the inter-dependencies. In fact, when you say the "module for GUI" I'm not too sure what you're thinking of? Bio::Graphics maybe?
Two, what exactly are the tests that are failing? The identity of the failed tests (and what module they are against) will help you decide if this is something to worry about or not.
Three, if you are having problems, try asking at the bioperl help group (firstname.lastname@example.org). If this is a verifiable bug I'm sure they'd want to fix the problems.