The version for my Windows XP SP3 system is reported by JON as "Win32 5.1". It should instead be something like "Windows XP 5.1.2600 v.5503 SP3".
Setting to future
This bug was previously known as http://jira.rhq-project.org/browse/RHQ-181
Mass closure per triage. If you consider this a critical issue, the bug may be reopened later for future consideration.