Add File Limit for the Downloadable Product

Hi, I have created a Downlodable Product, which is having more than 1000 downloadable files. I have to give these as separate files itself. But after adding 304 files, it is not taking any more files to save. It is showing to add files, after adding and updating it is coming back to the last 304 file. adding more than 304 downloadable files to a product and the 305th is simply not getting saved. So how can I add more downloadable files to single product