Web Forms :: Changes Not Showing Up Unless Hit Control F5?

I have a webforms project in Visual Studio 2008. In the page load I have some code like:

Label1.Text = "Hello"

Compile, run, it shows up fine.

Then I change the code to Label1.Text = "Bla Bla"

Compile, run, the label still says "Hello."

I thought maybe it was just caching or something, so I compiled and deployed the project to my server. The label STILL says "Hello" on the server. That could not caching, could it? The page address in the browser while running locally is totally different than the page address when viewing in on my server.

Someone told me to hit Control F5 in the browser, and on BOTH the server, and on my development machine, the text changed to "Bla Bla."

This only seems to be happening in one project (and so far at least, on this one page.)

What is going on here? Why just this project? I would think any change in my code, when compiled, would show up immediately.