The prelogin packet used to open the connection is structurally invalid; the connection has been closed

Today one of our developers was trying to call the Log operation of our AuditService running on his development sandbox but the entries were not added to the database and in the event log we saw the following entries a couple of times:

Here is the text of the entry:

Event Type:    Error
Event Source:    MSSQLSERVER
Event Category:    (4)
Event ID:    17828
Date:        17/12/2007
Time:        10:24:25
User:        N/A
Computer:    <removed>
Description:
The prelogin packet used to open the connection is structurally invalid; the connection has been closed. Please contact the vendor of the client library. [CLIENT: <local machine>]

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
Data:
<removed>

Looking at the version number of the SQL Server 2005 Developer Edition installed on this machine I saw that this was the RTM version. Hoping that patching it with Service Pack 2 would fix the issue we installed it and the problem was solved.