Thanks this looks like it might fix the issue I'm having but I did find this....
SSID scan technique; 0 (default) or 1. Technique 0 scans for the
SSID using a broadcast Probe Request frame while 1 uses a
directed Probe Request frame. Access points that cloak them-
selves by not broadcasting their SSID require technique 1, but
beware that this scheme can cause scanning to take longer to com-
So I guess this won't fix the issue on networks with a hidden SSID?