failed to open stream on WP 2.8.4

[wgrant]

Hi,
I have installed the Corporate theme so far on two sites with no problems ( a few months ago). I have recently tried installing it on a couple new sites but I keep getting the following error message when I try to upload it:

Warning: file(/mnt/w0710/d01/s04/b02c357b/www/calgaryoptometrists.ca/wp-content/themes/corporate-60192/style.css) [function.file]: failed to open stream: No such file or directory in /mnt/w0710/d01/s04/b02c357b/www/calgaryoptometrists.ca/wp-includes/theme.php on line 180

Warning: implode() [function.implode]: Bad arguments. in /mnt/w0710/d01/s04/b02c357b/www/calgaryoptometrists.ca/wp-includes/theme.php on line 180

I saw on one of the threads that others have experienced the same problem but I tried to implement the recommended fix from Adew which was as follows:

"I think the problem is that the ZIP file, when unzipped, creates a top level folder called corporate-60192 which contains the actual theme folder - hence the path to style.css isn't found. You can sort this out via FTP - just move the contents of corporate-60192 up one level, then delete the empty corporate-60192 folder when this is done. Does that make sense?"

unfortunately it hasn't worked. Any suggestions would be appreciated.
Thanks
Wayne (www.calgaryoptometrists.ca)