Error Acrobat Reader: Max Number of Files already open

Hi,
Using acrobat reader when I open multiple .PDF files after opening approximately 10-11 files, this error occurs.

"The maximum number of files are already open. No other files can be opened or printed until some are closed.'

Is this error documented some where on adobe site or some where else? Does any one know anything in detail about it.

Kindly let me know.

Thanks and regards