You almost certainly broke something. Netscape works fine on several different systems here. In fact it works great because of the magic wrapper scripts Debian installs.
I suggest reading: http://www.debian.org/~hp/tutorial/debian-tutorial.html/ch-docs.html#s-docs-support then asking again. In particular, include the *exact error messages* and the dpkg --status output for relevant packages (e.g. Netscape). Without these details all we can say is "works for us." Havoc