ศาลาชุมนุม

I have started learning Lao, and have had some Lao lessons at a school in Vientiane (at the ARDA Vientiane Language Centre). I speak Thai at a high level, which of course is very helpful in starting to learn Lao, but I am stuck on what the tone rules really are. My teacher is great, but like many native speakers, my teacher is not good at identifying the rules that govern pronunciation, and doesn't seem to mind my incorrect use of Thai tones in Lao. I appreciate the tolerance, but it doesn't really help me get things right.

A web search came up with these two seemingly helpful tone charts for Lao, but they are not the same:
http://www.phutai.thai-isan-lao.com/ima ... ai-lao.gif
http://www.thailao.net/graphics/wholechart1.gif

For example, the first chart shows a mid tone for high-class and mid-class consonants with ไม้โท, but the second chart shows these as falling. Other differences in there, too.

I am hoping someone can tell me:
1) Is one of those charts better?
1) Where can I find a good Lao tone chart? (for the dialect spoken in Vientiane, please)
2) Is there a good resource for learning Lao for Thai speakers? I have searched in Thai, and found almost nothing. There is some stuff for Thai speakers interested in learning Isan, which is helpful, but I am looking for something that also includes the tones and Lao script. Stuff aimed at native Thai speakers usually skips the tone rules.

I have been putting together my own set of vocabulary and grammar rule changes, but I was wondering if someone out there has already put something together.

Benjawan Poomsan's 3-way dictionary seems really helpful (sure wish it were an app like her Thai Talking Dictionary app), along with the Lao for Beginners book, but it would be great to see a collection of rules comparing Thai and Lao.

Any guidance much appreciated!

You've confused yourself with the first chart, which is two charts in one. The top chart is Siamese, and the bottom one is 5-tone Vientiane Lao. There is, or was also, a 6-tone Vientiane accent, and the second chart warns about that one. The two charts agree for 5-tone Vientiane Lao.

The tone charts seem to be defective in reverse. They don’t tell you how to write a high tone with a mid-class consonant (I think mai ti is the answer) or a low-falling tone with a mid-class consonant. While the combinations may be rare for historical reasons, I find it hard to believe they don't exist.