I'm implementing integration of live support and seem to be having problems w/ the live support operator client (the one you install from the MSI installer) garbling the cookies.

In my global.asax SupportLogin() API, the following cookies are set:
ecm cookie:
user_id=1&isMembershipUser=0&site_id=/websrc/WorkArea/&userfullname=Application+Administrator&displayname=&username=admin&new_site=/websrc/WorkArea/&unique_id=2099896832&editoroptions=ewebeditpro&site_preview=0&langvalue=&isMembershipUser=0&DefaultLanguage=1033&NavLanguage=1033&SiteLanguage=1033&template=&folderid=&width=790&height=580&FolderPath=&DisplayBorders=1&DisplayTitleText=1&UserCulture=1033&LastValidLanguageID=1033

EktGUID cookie:
dc06a2d0-6727-491f-afa7-d10e03dfe88b

ASP.NET_SessionId cookie:
5jiwji55ksbii445fgt2nnip

.ASPXAUTH cookie:
E74DE98E417C8E6FC2095668DB6D7DC36855B597EC8C1A82FE4B832667EC8C319847960E33F0DFB204F87ADA65819AEBD2934A35146DBF57FB279D83C9F99DBD03D49A9A1C6782981344821F909825F2


When the live support client calls the global.asax GetUserIdentity() API, the HttpContext.Current.Request.Headers("Cookie") is this:

ecm=user_id=1&site_id=/websrc/WorkArea/; EktGUID=dc06a2d0-6727-491f-afa7-d10e03dfe88b; .ASPXAUTH=E74DE98E417C8E6FC2095668DB6D7DC36855B597EC8C1A82FE4B832667EC8C319847960E33F0DFB204F87ADA65819AEBD2934A35146DBF57FB279D83C9F99DBD03D49A9A1C6782981344821F909825F2F839481DC039E572798061E34608A21C92B46566A6D0FDA650CB549256980BAC; 2099896832&userfullname=Application+Administrator&displayname=&username=admin&new_site=/websrc/WorkArea/&unique_id=2099896832&editoroptions=ewebeditpro&site_preview=0&langvalue=&isMembershipUser=0&DefaultLanguage=1033&NavLanguage=1033&SiteLanguage=1033&template=&folderid=&width=790&height=580&FolderPath=&DisplayBorders=1&DisplayTitleText=1&UserCulture=1033&LastValidLanguageID=1033; ASP.NET_SessionId=khuxdenbeoirs1n5kzi4dx55

Note that the ecm cookie has been chopped in half and the other cookies are stuck into the middle of it.  This is the raw cookie HTTP header, so I'm pretty sure it's being sent over by the live support operator client.
There's no version information on the login screen for the live support operator client, but it's from the 9/25/06 download of live support.  The MSI file is dated 7/30/06.