Very odd, new install on Windows 7 DNN 5.1.2

I know this is a crazy amount if info but I figured I'd provide as much data as possible...

When I MouseOver the EditMenu dropdown I get the following error...

Message: Sys.ArgumentException: Cannot deserialize. The data does not correspond to valid JSON.
Parameter name: data
Line: 6345
Char: 5
Code: 0
URI: http://localhost/dotnetnuke_community/ScriptResource.axd?d=fB9_GGa1jHe9sCOk63bqFweyz_EG5pS6-j34Zt3H1EL85V2Z7_IMykJzbl_45u-bzhSDnZ4BD0kIphFVk46TLsYr84O-DpLV9GswIqbTkK41&t=ffffffffec2d9970

If I run it from VS2008 it directs me to here...

ScriptResource.axd 

function Sys$Serialization$JavaScriptSerializer$deserialize(data, secure) {/// <summary locid="M:J#Sys.Serialization.JavaScriptSerializer.deserialize" />

Exception on this line "return eval('(' + exp + ')');"

"exp" variable =
nodes:[{id:"1",key:"1",txt:"Edit Content",ca:"3",url:"/dotnetnuke_community/Home/tabid/39/ctl/Edit/mid/353/Default.aspx",img:"/dotnetnuke_community/Images/edit.gif",nodes:[]},{id:"2",key:"2",txt:"My Work",ca:"3",url:"/dotnetnuke_community/Home/tabid/39/ctl/MyWork/mid/353/Default.aspx",img:"/dotnetnuke_community/Images/view.gif",nodes:[]},{id:"3",key:"3",txt:"Export Content",ca:"3",url:"/dotnetnuke_community/Home/tabid/39/ctl/ExportModule/moduleid/353/Default.aspx",img:"/dotnetnuke_community/Images/action_export.gif",nodes:[]},{id:"4",key:"4",txt:"Import Content",ca:"3",url:"/dotnetnuke_community/Home/tabid/39/ctl/ImportModule/moduleid/353/Default.aspx",img:"/dotnetnuke_community/Images/action_import.gif",nodes:[]},{id:"5",key:"5",txt:"Help",ca:"0",url:"/dotnetnuke_community/Home/tabid/39/ctl/Help/ctlid/202/moduleid/353/Default.aspx",img:"/dotnetnuke_community/Images/action_help.gif",nodes:[]},{id:"6",key:"6",txt:"Online Help",ca:"0",url:"http://www.dotnetnuke.com/default.aspx?tabid=787&helpculture=en-us&helpmodule=HTML",img:"/dotnetnuke_community/Images/action_help.gif",nodes:[]},{isBreak:"1",css:"ModuleTitle_MenuBreak",nodes:[]},{id:"8",key:"8",txt:"Settings",ca:"3",url:"/dotnetnuke_community/Home/tabid/39/ctl/Module/ModuleId/353/Default.aspx",img:"/dotnetnuke_community/Images/action_settings.gif",nodes:[]},{id:"9",key:"9",txt:"Delete",js:"if(confirm(\'Are You Sure You Wish To Delete This Module ?\')){__doPostBack(\'dnn$ctr353$dnnACTIONS$ctldnnACTIONS\',\'9\')};",ca:"2",img:"/dotnetnuke_community/Images/action_delete.gif",nodes:[]},{id:"10",key:"10",txt:"Refresh",ca:"0",img:"/dotnetnuke_community/Images/action_refresh.gif",nodes:[]},{isBreak:"1",css:"ModuleTitle_MenuBreak",nodes:[]},{id:"12",key:"12",txt:"Move",ca:"0",img:"",hasNodes:"1",nodes:[]}]

It's a brand new clean install. No modifications whatsoever. I haven't even created a page yet. I log in as host, and MouseOver the Menu DownArrow besides "DotNetNuke Community Edition", the AJAX .gif starts spinning and the error shows up in the status bar.

I did get the same error today.. think it was after I did do a /Install/Install.aspx?mode=installresources as I did have some old crap in that folder. After some hours of research I did found out that my problem was in js/dnn.xmlhttp.js and after replacing that file with the on from the upgrade file "DotNetNuke_Community_05.01.02_Upgrade.zip" that I did install last week, everything started to work as normal again.

Don't know if that helps anyone, but saved my day.. was so close to reinstall the whole site.. its my development site, but have many custom stuffs done to it.. so it should have taken many hours.