RST 38 error .. DC 9.50

I am getting an error
RST 38 occured, but RST 38 vector unintialized
Address : 04: 5585
What that means???
This error come sometimes when i upload data through http and when data uploading get succeed, and when I close the socket, this error come, but again not every time. What might be a problem. How to solve??
Thanks in advance