I've used Time::HiRes over the years -- many different versions, on Linux, Solaris, and Windows. Everything from little throwaway scripts to high-performance, mission-critical apps. Never once had a problem with Time::HiRes. Never.
It's far, far better than perl's default (and clumsy) command-line debugger. perl -d is okay for trying things out, and experimenting with the language, but for debugging actual programs, you need ptkdb.
Also, this is the only debugger I know of that enables full-screen on-demand debugging of CGI programs. If you have an X server, and your webserver is apache/*nix, you can set it to pop up on your display when you visit a CGI program in your browser. OUTSTANDING.
