Cart total is 1/2 what it should be, production site down

Hello,
I have a prouduct price setup at $4.00, my Product Qty Minimum: 0.5, Product Qty Maximum: 10 and Product Qty Units:0.5.

The problem is when a customer adds .5 units to their cart, the total is $2.00 instead of $4.00.

Last week, when they added .5 to their cart, the total was $4.00, I have no clue what I changed to make this happen, any help or info would be greatly appreciated.
Thanks!!!

Any Help Would Be Greatly Appreciated as this has had my store down all day....

See picture attached..

When customer adds .5 units to cart and unit price is $5.00, $2.50 is displaying in the cart, not $5.00. I have checked everything and this worked great last week.

Please help if you can

Thank You very much!!!

That looks very strange...........

Hi everyone!!

Can anyone help me with finding out which module or php file handles the price calculation in the shopping cart? I have a serious problem in my store, after a user adds an item to their cart, the total price is cut in half.

I just need a place to start looking as I am very new to Zen. Also attached is a screen shot of the problem.

Thank in advance.

Your product price is $4 - you put half of one (.5) in the cart - then $2 **IS **the correct price.

BTW- Posting and reposting the same problem in multiple places is not going to get a faster response.