I just did a border bounce at the Chiang Kong - Huay Xai border. Got a visa on arrival in Lao then turned around and went back to Thailand. I had my dtv acceptens document printed out and gave it with my passport to the immigration officer.
I was asked verbally how long i will stay in Lao by Lao immigration officers and panniced and said one week. So then also wrote 7 days on the paper you need to fill out. But they didnt care when i exited Lao minutes later. The thai immigration officer asked me if i still stay in chiang mai and i said yes.
I drove my self from chiang mai. Most of the road is under construction. Wasnt the nicest ride by motorbike.