Can't install Extensions in 2.0 with Multizilla enabled

With Multizilla's XPInstall confirmation window on OR off, nothing 
happens and I get this if I try to install from an untrusted site:

Error: uncaught exception: Load of 
https://addons.mozilla.org/downloads/latest/1865/adblock_plus-0.7.5.4.xpi denied.

Error: [Exception... "Component returned failure code: 0x80004002 
(NS_NOINTERFACE) [nsISupports.QueryInterface]"  nsresult: "0x80004002 
(NS_NOINTERFACE)"  location: "JS frame :: 
chrome://multiviews/content/multiviewsInit.js :: anonymous :: line 394" 
  data: no]
Source File: chrome://multiviews/content/multiviewsInit.js
Line: 394


----------------------


 From a trusted site, I get the following

Error: uncaught exception: Load of 
https://addons.mozilla.org/en-US/firefox/downloads/file/37745/noscript-1.8.1.3-fx+mz+sm.xpi 
denied.


And I also get a little popup window that if I resize, says this

FILE NOT FOUND

The file 
jar:file:///home/andrew/Programs/seamonkey/chrome/comm.jar!/content/communicator/xpinstall/institems.xul 
cannot be found. Please check the location and try again.