The 'listview virtualisation' error isn't to do with you using 64bit; Entity is compile as a x86 application (as are the majority of C# apps) which means it will run the same on 32 and 64 bit machines. It manages this by compiling the C# source code to IL source code, which is then converted to valid 32/64bit native code when you actually run the .exe by the common language runtime (CLR), using just-in-time compilation (JIT).
Virtualisation of listviewitems is useful when you know you are going to have many items in the list, and so you only want to create enough listviewitem instances in memory that will fill the listview
visually in order to save on a ton of memory: if you have 1000 items but only 10 are visible at any one time, you have only 10 listviewitem instances in memory and store the other information for the 990 items
virtually. Then when the user scrolls through the list you can just update the info showed on those 10 items with the info from your virtual database.
Anyway, in the case of a references viewer, there is no need for listview virtualisation, so you could likely remove that code and see no perf difference...
Troy, source control requires 3 things:
- A server to place the source code: this is where all the source code files are stored, as well as previous versions of those files which can be very useful; It's useful to be able to restore files to a previous state if you find something you did didn't work and broke everything

Software to access the online repository: This is how you access the server to either 'update' (download the latest source code), or to 'commit' (upload changed files). This is usually done by right-clicking the folder in which the solution file is located in windows explorer, and then either updating or committing the folder.
A visual studio plugin: This one is optional, but streamlines the above by being able to right-click the solution in the solution explorer and immediately update/commit from there. Also green and red lights next to each file indicate whether it is fully up to date or not.
At my university for example, repositories are located on the uni servers, the svn software we use is tortoiseSVN, and the plugin we use is visualSVN. None of that is free though, so if you want to go down the free route: you can use googlecode/ github/ codeplex/ sourceforge etc as the server, for the software there are numerous options (github offers it's own etc). For the plugin, there is a github plugin called 'git extensions' I believe. But you can only use plugins with the professional version of visual studio, so you may not have this option anyway.