Resolved Microsoft EXCEL 2007 help needed

I have an old program that keeps up with my stocks. It's at least 20 years old, and I don't recall where I got it and how I imported it into whatever original version of Excel I had at the time.
In columns A and B, I have the name of the stock.
Under column D I have the number of shares. Column F is price per share, and column H is the product of D and F.
I have 15 stocks and line 16 of column H shows the total sum of all the 15 sums above it.
I recently added a new stock, but when I enter the number and price of the shares, column H does not show the product.
When I enter its product manually into column H, the figure in line 16, column H adjusts correctly. However, if I adjust the price of the new stock, its product stays the same as before the adjustment.
The other 14 stocks behave correctly, and adjust column H.
I'm sure I used an incorrect step to insert this new stock.
Can anyone walk me through which method I should use to correctly enter the new stock so that it updates column H when I change its price?
Thanks.

 

Hey, thanks for the hint. I just now copied and pasted another stock's row, and then edited the resulting row with the data from the new stock. That seems to have solved the problem. I will mark this thread as solved.
Thanks so much.
Skaler2K