I suspect it is a change in one of the CPAN index files that occurred today that is causing your problems.
You could turn on verbosity, just to be sure
CPAN Terminal> s conf verbose 1
If it is as I suspect, then upgrading to the fixed version of CPANPLUS (0.9136) I released today should solve the problem
C:\> lwp-mirror http://www.cpan.org/authors/id/B/BI/BINGOS/CPANPLUS-0.
C:\> ptar zxf CPANPLUS-0.9136.tar.gz
C:\> cd CPANPLUS-0.9136
C:\> perl bin/cpanp-boxed
CPAN Terminal> i CPANPLUS