The presence of the name is required by the CRAM-MD5 mechanism definition.
The previous version was not in alignment with the specification, RFC 2195:
This produces a digest value (in hexadecimal) of
b913a602c7eda7a495b4e6e7334d3890
The user name is then prepended to it, forming
tim b913a602c7eda7a495b4e6e7334d3890
Mark Wahl, Enterprise Directory Integration
Critical Angle Inc.