title: Magento configure product regular price being set to zero when sale price occured
body: <p>I noticed a issue on my configure product today. and Hope all of you guys can help me solve this problem. 
  I am running magento CE 1.7.0 on the site.</p>
  
  <p>Here is the issue link 
  <a href="http://fishermandepot.com/best-deals/yo-zuri-surface-bull-gt-popper.html#.UOyhGKz5VHA" rel="nofollow">http://fishermandepot.com/best-deals/yo-zuri-surface-bull-gt-popper.html#.UOyhGKz5VHA</a></p>
  
  <p>The issue happened as if you choice the drop down options for a sale item, it displayed on that page as</p>
  
  <p>Reg:0 Sale:28.99 instead of Reg:33.99Sale:28.99</p>
  
  <p>If you did not click the drop down choice, price display correctly.</p>
  
  <p>I checked the back end, all the child product has correct original price and sale price. 
  Add to cart function still has correct sale price.</p>
  
  <p>I tried to go over the code. But not sure why it went wrong. Since if no drop down being selected. It will display properly once the drop down being involved, it does not work properly.</p>
  
  <p>Hope you guys can help me out and solve this problem.</p>