BTW, have you experience converting from Framework 2.0 to Framework 3.5 and to the new version of VS.

>>They both are 3.5.0 already. However, several other references are 2.0 Should I try to update them?
>
>No, that shouldn't be necessary. Most of the other references haven't been updated to a 3.5-specific version.
>
>Did you upgrade the AjaxControlToolkit as well? If not, that's probably the source of your error.
>
>>
>>Also why do I need Windows Form in a WEB application?
>
>I've noticed that as well, but I've never had time to investigate it.
>
>>
>>Do you know how can I copy the references and their versions, BTW? This dialog doesn't seem to allow copy them.
>>
>
>Sorry, no.