I’m new to wordpress also and I also had a couple of problems with uploading a new logo.
Here are a few tips.
* While developing and trying out logos, disable wp-caching
found under WP-Cache. I think that not only does the browser cache
but also WP.
* the logo is placed in
wp-content/themes/wp-creativix/images/logos
so verify that the image has read access for both group and
public (e.g. 644). I use the ftp tool filezilla to
change the permissions remotely.
* Load the logo from WP-Creativix Options Page rather than the
Header Option
