Images replaced via ftp not showing up on site

[#1]

Hi
I have uploaded a wordpress site into a subfolder on my ccgi webspace, I have finally managed to get it working using the file permissions script supplied in this forum.  I am able to upload images and they work.  However, I have some other images I've changed (but kept the same name) related to the design of the theme.  These go in the themes/theme-name/images folder and I am transferring the altered images via ftp replacing the theme images that are there.  However, when I do this the image just disappears from the site - the original theme image has gone and the image of the same name that I have made changes to doesn't appear.  
I have checked the permissions of the /images folder - 750, the images are all 640, can anyone help?  Is there a solution I've missed as to why the design images don't show up?
Thanks in advance.

[#2]

Have they been replaced with .JPG instead of .jpg or vice versa?

[#3]

Those file permissions should be OK.
Did you upload the images using a binary transfer (auto should work)?
Can you see the image if you specifically browse to it?
eg
http://<ccgi domain>/<blog_folder>/wp-content/themes/<themename>/images/<imagename.typ>

[#4]

Hi, they are .png's and .png hasn't been replaced by .PNG - the names are identical!  Thanks

[#5]

When I go to the url of the image I get a message - Image (url) cannot be displayed, because it contains errors.  The image was fine on my localhost.  I uploaded the images using ASC11 - but will give it a go using binary now...  Thanks

[#6]

Hi
It's working now!  Thanks.  A quick question, I've used some code I found on the forum to eliminate the /~username/ from the url, however if I go to http://ccgi.username.plus.com/sitename it diverts to http://ccgi.username.plus.com/scsc/ ; !  If I enter http://ccgi.username.plus.com/sitename/ i.e. with a forward slash at the end, it works.  The code I put into the .htaccess is: 
# BEGIN WordPress
RewriteEngine On
# Fix trailing slash problem
RewriteCond %{ENV:SCRIPT_URL} ^/~[^/]+
RewriteRule ^$ /scsc/ [R,L]
# END WordPress
And it does remove the ~username, however obviously I need it to work without the / at the end of the url.  I have no idea how to change .htaccess files except by copying and pasting code from somewhere!
Thanks

[#7]

Quote from: mssavvy

RewriteRule ^$ /scsc/ [R,L]

You need to replace 'scsc' in that rewrite rule with 'sitename' (the subdirectory name for your site). That value was scsc in the thread you copied from.

[#8]

Hi
Thanks it works!