I am not permitted to access your server and install the application if you wish us to perform the install you may purchase an install service. I can help diagnose what might be wrong to some degree and suggest how you can fix it.
Here are likely areas you want to check.
http://www.photopost.com/installphp.html
1. Your using the proper server paths etc now it looks like you might be but before it definately was an issue of you using a url based on your error.
2. Make sure the directory data and its children are all 777 permissions.
3. check under phpinfo that safe mode is off anf file uploads is on.
If all of this is done you should be able to upload or you should get some kind of error so that we can assist further