Storage.pm line 1596 (getListOfWebs):

@webList =
    grep {
        $security->checkAccessPermission( 'view', $user, undef, undef, $_ )
    } @webList;

Depending on the UserMapping-module there might be a lot of code behind checkAccessPermission(). The code above depends on $_ not being changed by the called code. Please change it to something along the lines of

my @wl;
foreach (@webList) {
    push ( @wl, $_ ) if $security->checkAccessPermission( 'view', $user, undef, undef, $_ );
}
@webList = @wl;

I know its not half as elegant but much safer. And its quite hard to diagnose if you are bit by this.

my @blah = (
   [ 'A', 'a', 'B' ],
   [ 'X', 'y', 'z' ],
);

foreach (@blah) {
   print join(',', grep {$_ =~ /[A-Z]/} @$_),"\n";
}

While I agree that $_ is a horrible concept, there is nothing wrong with the above code. Discarded.

CC