Errors from a .NET 3.5 project show up as .NET 2.x

While my ASP.NET project uses version 3.5 of the framework, the event log registers errors as coming from version 2.X of the framework such as this:

Event Type:         Error
Event Source:       ASP.NET 2.0.50727.0
Event Category:     None
Event ID:           1334
Date:               2009-05-19
Time:               17:04:29
User:               N/A
Computer:           XXXXXXXXXX

Description:
An unhandled exception occurred and the process was terminated.

Application ID: /LM/W3SVC/234989001/Root
Process ID: 8912
Exception: System.Web.HttpException
Message: The remote host closed the connection. The error code is 0x80072746.

.NET 2.0, 3.0 and 3.5 are all based on the 2.0 CLR. The version you see is the CLR version, not the Framework version, so everything is fine.