If you are using version 1.48.66 or later, you can fix this issue by deleting your vfs preferences ini file. It's located in
Windows 7:
C:\ProgramData\ASGVIS
Windows XP:
c:\Documents and Settings\All Users\Application Data\ASGVIS
OSX:
/Library/Preferences/Qt/ASGVIS
This file is responsible for remembering window size and position, as well as a few other settings behind the scenes. You could also edit the file so that only the part responsible for the options window's position gets removed, but it's easier to just remove the whole thing.
This issue should not occur in 1.49.01, so if you are using that version, we would appreciate it if you could send us a bug report about this issue: vfswip@asgvis.com