When using Netscape 4.61 Composer it continually abends with a Bus error. I have replicated this on several different machines running RH 6.0 and Communicator 4.61.
unfortunately, Netscape communicator 4.61 is full of bugs. We are not sure when there will be a future release of Communicator before the Mozilla project releases a browser. In the meantime, we have to recommend against not using the composer.
this should be fixed in the latest netscape in Raw Hide.