If a task is baselined (task_1, resource EM1 assigned for 120 hours, billing rate: 123 dollar) the correct BCWS values (or baselined costs per resource) are displayed.
In case of a formal change request it can be required to re-baseline this specific task. This can be done by first clearing the baseline of this specific task through 'Baseline - Selected Task(s) - Clear'. However, the baselined costs for the resources are not reset. They still contain the original baselined costs.
In case of a changed timeline, the baseline can be set again through 'Baseline - selected tasks - Set'. Also in this case the baselined costs are not changed and do still reflect the original baselined costs.
This makes a proper earned value analysis impossible when formal changes appear!
Note 1: This problem occurs in Open Workbench version 1.1.4.
Note: incase the project's baseline is cleared, the resource baseline costs are cleared properly. However it does not work in case you want to clear a baseline of a specific task.