workingwebsites on "CSS not showing up"

Hi, I'm having problems modifying my CSS. I'm editing the files from Sublime Text 2 and uploading them in filezilla. They change in the WordPress editor but they are still not showing up when I launch the webpage.

I had an old wordpress installed in the same data base, but I've already erase it completely (I don't know if this could have something in relation with my problem).

Thanks.

First Question: Are the files being uploaded?
Probably, but double check to make sure they're actually on the server.

Second Question: Is the theme reading these files?
Make a significant change to something common (Ex. Change the font colour of an h1 tag.) Upload, have a look.
If there's no change, have a look at the code through your browser ('View Page Source')
Look through the code and see if you can find your CSS file.

Third Question: Is the changes you made just aren't showing up because of CSS issue?
It's easy to make a change and not have it show up because of the nature of CSS. Try making a really simple obvious change to the CSS file and see if it comes up. (h1 tag change)
If it does, then check the CSS you want to change again.

Can you please post a link to your site, and describe the element whose CSS you are trying to change?

I'm using a theme I made myself,I used it before and it worked perfectly.The files are being uploaded to the server, cause if I have a look to the WordPress editor they change also, but if I try to see them in the webpage and they are not showing up, I open the view source code panel and the changes are not there even when they appear in the WordPress editor and in the file I uploaded.

My site is almost empty, because I just started working in this new site and the problem is there almost since the beginning.

"I open the view source code panel and the changes are not there even when they appear in the WordPress editor and in the file I uploaded."

Sounds like the website isn't reading your files properly. Let's check that.
Is the style sheet file you're uploading referenced in the source code?

If you see the .css file you uploaded in the source code, open it in your browser and check to see if your changed code is in there.

(yes, a link to your site and the element would help us)