I just tested it in a sub folder and it works fine.
Steps I took:
- Created a folder call powergallery
- Gave it full permissions
- Created Database through cPanel
- Added user with full permissions to the database
- Uploaded PowerGallery into the newly created powergallery folder
- In browser, went to domianname.com/powergallery/install
- Followed wizard
- Hit Preview to look at my new gallery
Yes the new wizard is slick.
BTW I have heard many problem associated with GoDaddy hosting. GoDaddy as a registrar - good
GoDaddy hosting - not-so-much
Almost forgot. Don't forget to delete the install folder after the installation part is finished.