It sounds like it.
I had the same deal with my PC when I had an ArcadeVGA AGP card installed. I couldn't get a display, until I tossed in a PCI video card and hooked it up to that.
It would be nice if the Arcade VGA could also work at higher frequencies for the time you're configuring everything before hooking it up to an arcade monitor, but oh well. Most motherboards these days have an onboard video card that can be used in the meantime.