Vientiane have written several different comments on my B-visa in the past but its never been an issue.They seem to be a law unto themselves at the moment.
if you have a work permit you can get another 90 day non-b with the relevant documents from your employer and continue working while arranging to change to non-o
they all write this on 90 day non b's...getting another from KL will not be a problem...avoid Laos though as at present I beleive they won't issue back to backs