Don't `use vars`. It's been obsoleted for a long time and may disappear in future versions of Perl. Any of these options will work:

```perl
our @ISA;
use base qw(CAF::Application CAF::Reporter);
use parent qw(CAF::Application CAF::Reporter);
```
Ideally, you'd use `parent`, but I don't know if it is available on RH4 or Solaris 10.