Inventory Stock Not updating

Hi,

I have several products that I have selected track inventory and set the stock quantity to 1000.  I save it and it says it saved.  Then I sell one and it shows a negative stock quanitity and shows up on the Low Stock Report.    I have tried save and save and continue editing.  I have tried clearing the cashe and restarting the application.  Nothing seems to make a difference.

Version 4.2

Thanks in advance for any suggestions or solutions!

The question is actually saving the value 1000
Edit the product and tick Display stock quantity and ensure Backorders is "No Backorders"
Display the product and check what says in Availability: 1000 in stock
If not correct check for script errors on the Admin product page