This patch addresses a problem with the default httpProxyURL which should be relative to the current deployment, but in 5.5.1 is actually set to the absolute value /isomorphic/HttpProxy. This default setting works fine when the application is deployed at the root of the application server, but fails otherwise.

//----------------------------------------------------------------------------
// Isomorphic SmartClient v5.5.1 patch
// Purpose: Fix proxy URL not being relative to isomorphicDir and
// therefore failing for non-root deployments.
//----------------------------------------------------------------------------
if (isc.buildDate == "2006-12-12") {
isc.XMLTools.httpProxyURL="[ISOMORPHIC]/HttpProxy";
}