What state was the store in before the 4.5 update came out?
In other words, had you already entered a lot of products in the database and done some editing to the design?
or where you just testing it out?
If you where just testing the waters, then it would be better to do a fresh install rather than an update. delete all of the power store files from the live server, delete the database then upload the new 4.5 files and run the install wizard.