Dreaded Permalinks Issue

So I set up a site for a client, to this say xyz.com. He is getting sued over the company name so to avoid legal trouble he changes the name to abc.com. Now mind you I set up his hosting and wp with simple scripts install to xyz.com domain. I then changed the domain to the primary (abc.com) and set up wp to work with abc.com. THis is all with permalinks on, working perfectly. I start configuring stuff this is still working for 1 week. tonight I am messing around in wp ecommerce plugin and delete a slug name for a product category and rename it. Save and I believe I changed something else, it freaking destroyed the permalinks, they no longer work. I have tried redoing my .htaccess file to no avail. I tried numerous other things not working. I set up no permalinks and it works fine.

I engage my host. who seems pretty crappy but anyway, they set it back to the primary domain and wham it starts working with permalinks. I set it back to abc.com domain, stops working…anyone know if this is a coincidence but my host says

We apologize for any inconvenience this has caused you. I have checked the issue and found that you have installed WordPress application at xyz.com via SimpleScripts. If you wish the links of the website abc.com to redirect to the domain abc.com, please install the WordPress application for the domain abc.com via SimpleScripts and point the domain abc.com to different folder and take the backup of the Database: xxxx to the other database which is created via Simple Scripts from your end.

That seems quite verbose and stupid, I shouldn’t have to reinstall wp. HELP!