Asterisk Manager API broken on Asterisk 1.6.0.3 onwards

I just noticed this. It seems that the manager API is broken on version 1.6.0.3 onwards (also on 1.6.0.5). For some reason my application runs well on Asterisk 1.6.0.1 but not on later version. Are there any changes on the AMI architecture from 1.6.0.1 to latest version. I noticed this especially on Originate function on AMI. Has anybody experienced that??? Please advise. Thanks.