Index: webbrowser.py
===================================================================
--- webbrowser.py	(revision 54463)
+++ webbrowser.py	(working copy)
@@ -32,7 +32,11 @@
     for browser in alternatives:
         if '%s' in browser:
             # User gave us a command line, split it into name and args
-            return GenericBrowser(browser.split())
+            cmdline = browser.split()
+            if cmdline[-1] == '&':
+                return BackgroundBrowser(cmdline[:-1])
+            else:
+                return GenericBrowser(cmdline)
         else:
             # User gave us a browser name or path.
             try:
@@ -158,7 +162,8 @@
         else:
             # name should be a list with arguments
             self.name = name[0]
-            self.args = name[1:]
+            self.args = [arg.replace('"%s"', "%s").replace("'%s'", "%s")
+                         for arg in name[1:]]
         self.basename = os.path.basename(self.name)
 
     def open(self, url, new=0, autoraise=1):