Ghost Variables?

I am currently developing an Order Entry application in C#. The order entry process follows a wizard-like format.

We have a class, WizardBase, that contains the screen to display.

At one point, I had enabled /unsafe code in the project properties. I had also enabled Optimized Code.

One of my team members noticed that he couldn't properly declare variables in any function. We tried, and the variable declaration was sporadic at best, most times it didn't work at all. Here's an example of what I am saying:

int i = 0;

Breaking on this declaration and viewing i in the watch window, would report "i does not exist in the current context."

And now, we have a persistent variable, 'a', that is an object, and it has the following members:

base

nonpublic-members

-d = a.b - a.b

-e = a.c - a.c

-f = a.c - a.c

-g = 1385422863972036620 - long

After extensive searching through our project, we have determined that nowhere in the project is an object of 'a' declared, furthermore there are no d's, e's, f's, or g's, and that number assigned to g is strange.

This is the wierdest thing I have ever seen in Visual Studio. Anyone seen something like this