I have ESSO doing Single Signon with my WebSpher Portal. It works.
But I see a problem that looks like it comes from portlet URLs that are long.
I am talking about the URLs that are used inside portlets for triggering a reload of the portal page, causing one or more portlets to react on what was clicked. These URLs tend to always be extremely long.
When I click the longer ones, the browser (Internet Explorer) instantly reports a "Cannot find server" (Window title) and "The page cannon be displayed".
I have had a look at what's going on using IEHTTPheaders. It looks like the browser removes some characters from the end of the URL.
It also looks like the browser fires two GET commands.
Finally - I have done a tell booster debugheaders on - I can see that when I do click one of these URLs, booster apparently doesn't even receive the GET from my browser.