I have a 1 year Toshiba Satellite L755 that I've connected to my TV using both VGA and HDMI cables, and they work fine. That's the closest to having a match to your configuration I can come. I haven't tried it with an actual monitor, but both ports work fine with the LG 47SL90 TV. Have you checked your Device Manager to be sure you don't need a driver? That would be the first place I'd check.
I've recently gottan my hands on a Cintiq 22HD pen display. I've installed it on my Toshiba Satellite C655, however, even with the use of a DVI to VGA adapter, the computer does not register a monitor.
I've tried it on a different laptop and it recognized that there was an external monitor, so it shouldn't be the adapter.
Driver are something I have also looked into.
Any help on what the problem may be? The tablet aspect works fine, but the computer acts as if there was no monitor, or really anything, plugged into the VGA port.
TL;DR - Laptop doesn't register Cintiq 22HD's monitor.
Thanks in advance.