You may have noticed that the Xigla Live Support 5.2 product doesn't work on AC7 product pages. It seems to work everywhere else. But for some bizarre reason, products using product.aspx as their product page will break. Clicking the live chat link will result in the popup chat window returning an HTTP error 404 page not found.
Interestingly enough, the 404 error page has more information that it shows. If you right-click the page and choose Show Source, you'll see the exception trace stack that resulted in the error.
The question of WHY this happens is beyond my skillset but I do know this much: something in the HTTP handlers is mis-interpreting the ref= parameter as an actual URL and attempting an HTTP redirect. However the handler doesn't get the fully constructed URL and thus redirects to an invalid page.
The solution: remove the ref= parameter off the url in als.aspx located in your livesupport install folder. Like this (I commented out the original line for safe-keeping):
'theurl=appsettings.applicationurl & "UserPreChat.aspx?ref=" & server.urlencode(ref) & "&d=" & d & "&u=" & u & "&bypass=" & bypass
theurl = appsettings.applicationurl & "UserPreChat.aspx?d=" & d & "&u=" & u & "&bypass=" & bypass