Background Information
We recommend that you maintain both Project Server 2003 and the Microsoft Project Professional 2003 desktop client at the same Service Pack (SP) level. Therefore, it is helpful that you know how to determine the current SP for each product.
Resolution
In Microsoft Project Professional 2003, click Help > About Microsoft Office Project. The current SP level is shown in the upper right corner of the dialog.
In Project Web Access, hover your mouse pointer over the Help link in the upper right corner of the page. The screentip reveals the current Build number, of which 11.2.2005.1801.15 is the Build number for SP2a.