Access to File denied

Hi,

I am running a program to upload materials in bulk into table MARA by uploading a text file. However, it is throwing me an error that "Access to file is denied". I got the error at FM 'GUI_DOWNLOAD'. After browsing also i did not reach any conclusion. The OS on my system is windows XP and I have changed the security settings on the SAP LOGON to disabled status. I have not left the text file opened. I am not sure what else could be the problem. Can anybody please help.