Receiving "Invalid character" error on page when control attempts postback after upg to VS 2005

[DCC700]

After upgrading a web application from VS 2003 to 2005 there is a page
where any control event that should cause a postback instead generates
an Invalid character error on the page. For example a drop down list is
set to AutoPostBack, and for OnSelectedIndexChanged should update the
values of other drop down lists. This page works fine in VS 2003, and
the other pages with similar controls are posting back fine in 2005.

Has anyone else encountered this? Does anyone know what is causing it?

 

[DCC700]

I resolved a similar error in VS 2003 where I was getting a web page
error 'Expected;' and ddl postbacks were not working. This problem was
due to the fact that I was assigning a client script to one of the ddls
but it was also set to autopostback so the generated onChange included a
call to my function as well as the postback call that .Net includes with
no semicolon separating the two commands. It looked something like:
onChange="myscript()__doPostBack(eventTarget, eventArgument)"

This was resolved by disabling the auto postback for the control.


I haven't gotten back to this issue yet, but I am wondering if the
answer could be similar.