ASP.NET framework issue, javascript code _ctl1:mainForm breaks IE, Error Expected ';'

[jbrag]

Hi

My 2003 and XP web application server machines have a problem related
to ASP.NET framework. The IIS/ASP.NET generates javascript code in my
Xxx.ASPX pages containing this fragment :

"theform = document._ctl1:mainForm;"
instead of standard: theform = document.forms["__aspnetForm"];

This is a part of automatically created function __doPostBack() by the
framework.
And it breaks under IE browser with "Error Expected ';'" alert box
displayed, when the page is served.

I know this is a known problem and there is a Microsoft KB article and
a patch for that.
Could anyone please point me to the article/patch ?
Thank you for help in advance!

For more on that problem (however incomplete info) see:
http://dotnet247.com/247reference/msgs/51/256272.aspx

Jacek.