Eclipse Ruby Debugger: Port 1098 problem?

I’ve read that Eclipse’s debugger will not work unless the Ruby
debugger is bound to port 1098. Anyone know a solution? There may be
another application binding to that port already, but is there a way
around it?

Title: Using the Ruby Development Tools plug-in for Eclipse
This article introduces using the Ruby Development Tools (RDT) plug-in
for Eclipse, which allows Eclipse to become a first-rate Ruby
development environment. Ruby developers who want to learn how to use
the rich infrastructure of the Eclipse community to support their
language will benefit.