FTP Folder Error

Every few minutes a window pops up labelled 'FTP Folder Error'. It states that 'Windows cannot access this folder. Make sure you typed the file name correctly and that you have permission to access the folder. Details: The connection with the server was reset'; its only button is 'OK'.
I have not tried to access FTP in weeks and, when I do, I use cuteFTP rather than DOpus.
I tried fiddling with the DOpus FTP settings under Preferences, but to no avail. Is this a DOpus (versions 9.0.0.2 and 9.0.0.3) problem or a Windows (XP Pro) problem?
Any help would be greatly appreciated as it is very annoying. I would hate to have to resort to an automatic button presser (PTFB, for example).

Are you sure this message is coming from Opus?

Could you show us a screenshot of the message?

It sounds like it comes from Windows/Explorer/IE:

support.microsoft.com/kb/260156

I finally tracked it down: an errant piece of software that had been working fine for a long time. Uninstalling and reinstalling seems to have solved the problem, but only after having to delete over six months of web history.
Thank you for your help.