I went over all of your posts since you first posted on here because I think your chameleon should be eating better. I'm worried that if he doesn't get the problems solved soon you will lose him. Sorry if I mention things that you have already corrected but its hard to remember everything you have said in so many posts.
Is your chameleon still shutting its eyes during the day?
How long have you had the long linear tube actually on the cage? It doesn't pass through any glass or plastic does it?
What is the temperature in the warmest area of the cage?
I explained in my post (post #3 in the same thread) how to dust...dust at all the feedings with a phos.-free calcium powder except for the two times a month that you dust with a phos.-free calcium powder and the two times a month that you dust with the vitamin powder. You could give the D3 on the first day and the 15th day of the month and the vitamin powder on the 7th and the 21st of each month leaving every other feeding in the month to be a calcium dusted feeding. Is this basically what you are doing now? Are you feeding it once a day? A young chameleon should be eating about 15 or so appropriately sized crickets each day. I feed mine as much as they will eat in a couple of minutes at each feeding and then leave a couple in the cage for a snack later on...and its always about 15 crickets.
Are you still using the blue light? All you need for a chameleon up to 3 or 4 months old is a long linear Repti-sun 5.0 UVB light and if that doesn't put the cage temperature in the warmest area of the cage into the low 80's you will also need a regular household incandescent light bulb in a domed hood. As the chameleon gets closer to being an adult you can increase the basking area temperature for a male veiled until it reaches the mid to high 80's for an adult male.
Did you get a fecal done?