The VSE Survey reports on donations based on specific categories of revenue and constituents, which are defined in Configuration. One of the categories of constituents is "Alumni" and organizations can map whatever CRM constituencies they'd like to this category. However, when mapping the system-defined Alumnus constituency to the Alumni VSE constituency and then running the VSE report, revenue given by constituents with the Alumnus constituency is not included in the report.
Download and install the latest patch, which contains all fixes from previous patches. If you are running an older version, download and install the latest version and then the patch.