Air overheating shop says needs Radiator

[littleant]

Just wondering what all you experts think? THey kept my car all day yesterday and said the reason it is overheating is the radiator needs to be replaced. I had it flushed twice and they even took it out and tried to flush it again but I am leary of replacing it because the car doesn't overheat except when the air is on and at night no problems at all.

I have $900 in this air fix already and if the radiator doesn't solve the problem I am out more money. I told him I would just live without air for the summer.

replaced compressor 7-1-03
replaced belt 7-2-03
repaced tension belt adjustor 7-15-03
replaced thermostat 7-16-03 (it was bad)
replaced thermostat again 7-16-03 (it was ok when taken out)

Help you wonderful experts!!!! Thanks so much