do you have an agressive virus scanning?
I've seen this behaviour too much scanning is active (it is a central administration in the company).
This will have a big impact to JBoss startup, java compiling and other ...
I suppose the admin console must compile some page after restart or redeployment.
On my environment (also XP and CentOS) the factor in some cases is >5, but I did not check AdminConsole yet.
Good suggestion, we do run an aggressive antivirus scanner in the dev environment. I'll look into it further.
For anyone else reading this thread, the problem does appear to be caused by something in our corporate SOE. I haven't been able to narrow it down to the exact software unfortunately, but the admin console is much more responsive in a cleam VM.