Jack,
Here are a few things that you can try,
Firstly check out which application if at all is using the port 1098. You can do this by using the netstat on the command prompt or by using this excellent
TCP view tool which lists all the ports.
On Windows platforms, you need to be aware of various services that will randomly take ports. Some examples are Windows Update, Exchange/Outlook, and as you noticed IM tools, and many more than can be listed.
For the safest bet on running production, you can keep the ports blocked from being used randomly. You can do this by following the procedure described over
the URL here Also other way would be to look at changing the port numbers used by Jboss (see service-binding-manager or something like that) to much higher number ranges to avoid this problem (particularly 1098 and 1099 ports).
Also remember if you have Microsoft Firewall Client for Microsoft ISA installed, then firewall client holds connections open for 4-5 minutes before releasing them. This will be the root problem. Disable the Firewall client.
Sandip