It could be an issue with the stick or the port. My development system has a USB port on the front panel that never works with Visopsys, and often causes trouble for Linux too. The ports on the back of the machine tend to work. I understand that it might have something to do with power (front port doesn't have the same level of available power, or something).
It might be a slightly fishy stick, too, and/or something that Visopsys isn't doing correctly. At the present time, Visopsys works with all dozen-or-so sticks that I own, running on real hardware. I've noticed some of them don't seem to work as well in VmWare since my last round of USB work

but that's the way it tends to go with hardware devices: It's tough to get everything just right for every system and every device.
The best way to make a bootable Visopsys USB right now would be to use the installer, as you already tried. When I do the next release (which is actually, basically ready - I've been working on a compression library for a future release) you'll be able to use scripts in the utils/ directory to create USB images.
Here's a USB image that I just created for you:
http://visopsys.org/files/misc/visopsys ... sb-img.zipYou can use a program like this one to write it to a stick:
https://launchpad.net/win32-image-writer/+downloadIf you're working with source code, I could give you the scripts to create USB images, but the last version of Visopsys really won't boot from USB anyway. The new release should be available in the next few days anyway.
Andy