dermit,
I would try making sure you got the files all uploaded into the correct folders. Specifically, if you changed the name of your admin folder as suggested by ZC on your hosting company, make sure you rename your admin folder appropriately before uploading craftzombies files. I have installed a small handful of contributions, but in regards to products I am running a stock 1.3.9f zen cart. I went through each of my folders, cut the files out which craftzombie would be replacing, and pasted them into a separate backup folder, retaining the structure (IE putting in an english folder or admin folder or includes folder as needed). If you do this, then rename the admin folder in the zip she uploaded, you should be able to just upload the two folders (the admin-equivalent and includes folders) and everything should be fine and upload to the correct places.
Also make sure you have set up your wholesale pricing correctly. Go in and verify you have the wholesale pricing set with hyphens between them on your products. 0.00-0.00-0.00-0.00 if you do not want to offer a wholesale price for a particular item, or 9.99-8.99-7.99-6.99 for instance if you wanted to offer 4 different wholesale price levels for an item.
Finally, make sure your customer account is set up with a 1-4 number to achieve the desired pricing level. This is set by a box underneath of the customer's email address. By default they are set to 0 which is a retail-only price level.
If you are still having problems, I can try to give you a hand and look over things/try to fix it, but it is my opinion if you are running a new ZC install, that it has to be a problem with the files not uploading correctly (as some FTP clients will do) or a setting within the admin area that needs adjusting since I am running a nearly stock ZC at the moment and it worked perfectly for me. Double check my suggestions, and then try re-uploading the two main folders in the attachment and see if it clears up your problem. If not, the contact page on my ZC will email me, feel free to contact me and I will see what I can do to help.
Thanks,
Joey Phillips
http://www.leatherbyjean.com/catalog -my ZenCart