If the update rdf for an extension includes a newer version, but that entry has no updateLink entry then the Add-ons UI displays the Updates pane but it is empty. The following is logged in the console: Datasource: Update Started Datasource: Addon Update Started: {20060223-1419-4d60-a070-3e1c1187f6a0} RDFItemUpdater:checkForUpdates sending a request to server for: http://users.blueprintit.co.uk/~dave/filestore/updates.xml, item = ({id:"{20060223-1419-4d60-a070-3e1c1187f6a0}", version:"0.2.1.20060304T0207", installLocationKey:"app-profile", minAppVersion:"1.0+", maxAppVersion:"1.5.0.*", name:"jTime", xpiURL:"none", xpiHash:"", iconURL:"chrome://mozapps/skin/xpinstall/xpinstallItemGeneric.png", updateRDF:"http://users.blueprintit.co.uk/~dave/filestore/updates.xml", type:2}) RDFItemUpdater:onDatasourceLoaded: Found a newer version of this item: ({id:"{20060223-1419-4d60-a070-3e1c1187f6a0}", version:"0.2.2.20061025T1237", installLocationKey:"app-profile", minAppVersion:"1.0+", maxAppVersion:"2.0.*", name:"jTime", xpiURL:null, xpiHash:null, iconURL:"", updateRDF:"", type:2}) Datasource: Addon Update Ended: {20060223-1419-4d60-a070-3e1c1187f6a0}, status: 1 ExtensionItemUpdater:checkForDone: Failure in listener's onAddonUpdateEnded: [Exception... "Component returned failure code: 0x80004003 (NS_ERROR_INVALID_POINTER) [nsIRDFService.GetLiteral]" nsresult: "0x80004003 (NS_ERROR_INVALID_POINTER)" location: "JS frame :: file:///C:/Program%20Files/firefox2/components/nsExtensionManager.js :: EM_L :: line 235" data: no] Datasource: Update Ended

This is an update rdf from an extension that exhibited this issue.

The patch for bug 378216 included a check to ignore updates without an updateLink so this should be fixed.