Passive Mode Question


I'm using a trial version and considering purchasing, however in the middle of my trial I am suddenly unable to connect to the server I am using. I believe it's because it's forcing into Passive Mode and the site I conenct to does not support PSV. I have made sure that the PSV box is unchecked, I am not behind any firewalls, not using a router. I've run a trace route from my my computer to my FTP site and everything is fine there. I have even connected to the FTP site from my mom's home (we use the same ISP company) without any problems. Just seems to be encountering problems from my PC. From what I can tell, there aren't any settings on my PC itself that have changed.

Any help or suggestions would be greatly appriciated. Thank you.