"The upload path does not appear to be valid"

[eluser]jedd[/eluser]
You could use the [url="http://net.tutsplus.com/videos/screencasts/easy-development-with-codeigniter/"]Net Tuts File Upload[/url] code as your base.

I rattled up a copy of their code and got it working in a few minutes (just needed to fix up their paths and my perms).

If you look at your web server logs you should be able to see where you are failing to have write permissions for the uploaded file - this will prove out that you are actually writing to the place that you believe you are writing to.

What permissions do you have on your upload directory at the moment anyway?