cannot upload


I have been using Smart FTP for some time and all of a sudden I cannot upload from my local to my website.

I left click on what I want to upload and then right click and drag. I can only drag it to the boundary of the local. It will not go up to download. I don't know what to do. It did this once before but seemed to correct itself.

Do you think it would help if I changed from the "passive mode" to the "active mode"? If so, please tell me how to do it.

Can anyone help me? I'm getting desperate.

Thanks in advance,