diff --git a/mobile/chrome/content/browser-ui.js b/mobile/chrome/content/browser-ui.js
index 1591f2364852..754361754e20 100644
--- a/mobile/chrome/content/browser-ui.js
+++ b/mobile/chrome/content/browser-ui.js
@@ -713,9 +713,10 @@ var BrowserUI = {
 
     let engine = Services.search.getEngineByName(aName);
     let submission = engine.getSubmission(searchValue, null);
-    Browser.selectedBrowser.userTypedValue = submission.uri.spec;
     Browser.loadURI(submission.uri.spec, { postData: submission.postData });
 
+    // loadURI may open a new tab, so get the selectedBrowser afterward.
+    Browser.selectedBrowser.userTypedValue = submission.uri.spec;
     this._titleChanged(Browser.selectedBrowser);
   },
 
diff --git a/mobile/chrome/content/browser.js b/mobile/chrome/content/browser.js
index 8d4b92693c4c..8189ce927189 100644
--- a/mobile/chrome/content/browser.js
+++ b/mobile/chrome/content/browser.js
@@ -601,8 +601,7 @@ var Browser = {
         this.closeTab(oldTab, { forceClose: true });
         oldTab = null;
       }
-    }
-    else {
+    } else {
       let params = aParams || {};
       let flags = params.flags || Ci.nsIWebNavigation.LOAD_FLAGS_NONE;
       browser.loadURIWithFlags(aURI, flags, params.referrerURI, params.charset, params.postData);
@@ -2942,7 +2941,7 @@ Tab.prototype = {
 
     try {
       let flags = aParams.flags || Ci.nsIWebNavigation.LOAD_FLAGS_NONE;
-      let postData = "postData" in aParams ? aParams.postData.value : null;
+      let postData = ("postData" in aParams && aParams.postData) ? aParams.postData.value : null;
       let referrerURI = "referrerURI" in aParams ? aParams.referrerURI : null;
       let charset = "charset" in aParams ? aParams.charset : null;
       browser.loadURIWithFlags(aURI, flags, referrerURI, charset, postData);