Remaining time is not identical on Version Workload and Time tracking report

I was encouraged after submitting a support case to report the following problem;

Why are the "Time remaining" estimates for the "Version workload" and "Time tracking" reports different?
.... the Version workload report says: 4 weeks, 2 days, 3 hours and the Time tracking report says: 6 weeks, 2 hours, 30 minutes for the remaining time ...

Emily Stumpf [Atlassian]: ... I loaded your data and was able to reproduce the problem

Emily Stumpf [Atlassian]: ... When I spoke to the developers they seemed to know that it existed, but since they didn't say it was only unresolved issues in the description, they didn't say that it was actually a bug, but that yes, it is at the very least confusing. I would recommend filing a bug report at jira.atlassian.com. I looked through a bit and did not see it listed previously (although it is possible that I missed it).

Please see the following support case for screenshot;
https://support.atlassian.com/browse/JSP-15841