Guys, I am SO sorry. I am at a loss on what to do. The stamp set I listed this week has had some issues in the shop. People who did purchase it, there was something wrong with their PayPal transaction (shipping addresses not pulling into PayPal from my shop), and at least one person simply couldn't order it at all.
I have sold digital and physical items this week without these issues, and I've spoken to PayPal and Storenvy's support teams and they couldn't help me at all. The only difference I can spot in this product vs. others in my store is the 99 cents on the end of the price. So instead of $6.99, I've changed this to $7.00. (And set up a new listing-I updated the links I'd posted previously). I am just so sorry for that extra penny.
I truly hope this fixes the issues that are happening with this set. If not, I may move it over to Etsy but I have hopes this fixes things. My apologies. I'll keep you posted.
Update: I had someone test this and place an order this morning and it works. The problems should be all resolved now. Thanks for everyone's patience and understanding.
Update 7/9/2013: This stamp set is now listed in my Etsy shop. Once again, my apologies for all the confusion.