@David ******
many of the smaller offices won't or can't issue 90 day Non-O visas. Bangkok, Chiang Mai, Phuket, Jomtien and a couple others can. Other offices will do it but you need more time on your current stamp because they send the paperwork to their regional head office for approval.
I'd say if you're after a Non-O visa based on marriage to a thai just go to Savannakhet Lao and get one..