During the day, my cage temps run from 71deg in the lower 1/4 of the enclosure up to the low 90's in the basking area. Feldman is able to take care of his thermo-regulation quite well. Night cage temps run between 65-70 degrees depending on elevation in the enclosure. 83-85 degrees for a...
Measurements I have taken show approximately a 50% reduction of UVB through the screening on my cages. The looser the mesh, the less UVB and visible light is reflected away from the cage.
Are you using a syringe with a ball tipped feeding tube? Properly used, this will make sure the liquid ends up in his stomach without any chance of aspiration. A vet or other individual with knowledge of chameleons should show you how to do it as well as suggest an appropriate amount of food...
I have the Exo-Terra Light cycle unit. The tubes are clipped into a pair of Arcadia reflectors (which were too expensive with shipping for what they are). They rest on top of the screen cage. I would save some money and use foil as Summoner suggested if I had to do it again. Also, the Light...
I would also suggest at the least taking a fecal sample to the herp vet for a smear and float. A parasite load can put them off their food and make them act as you have described.
Mine will do this too. I think they are waiting for their meal to be dead before sending it down their tender innards. I can't blame them for not wanting to swallow something that may be biting or trying to crawl out.