Works in my machine, but not in server...

I have developed my asp.net applications so far with asp.net WebMatrix and everything have been easy and fun. Now I'm working first time with Visual Studio 2003 and I have stupid problems.
Everything works fine in my machine, but when I transfer my files into the server my .aspx page won't execute it's source code.. First I get error; could not load type inherit="rengas._default", I did try to remove this line, but then it won't execute code..
Why this won't work in the server?!
I have other aspx applications in that server, but I don't use code-behind property in those apps.
Listen, you need to build your solution before deploying it.
And if the same error happens again and again, you will need to create a new page (aspx) with a bit different name and copy the code from the first one giving you errors to the second newly created one.
regards