Agi problem on vmware

i config an extension exten => 1000,1,aig(service.php). when the iax softphone dial the extension . the aig first answer it, then the softphone sendtext to asterisk. the agi try to get the text using receive text . i works fine on one machine. but when i configure them on a vmware host, agi receive text can not success . what 's wrong ? it is strange that one in hundred can success!

hi every one. really need your help. my iax softphone send text to asterisk ,i want to use ‘agi receive text’ to get it. it works fine on a machine.but when i install these scripts on another machine, it always
can not receive text. other aig command seems works fine. i using php to write agi programs. it there some settings in php or something else which prevent to do this? any hint will be great appreciated!

btw, it seems not vmware problems. i install this on a real machine ,the prolem still exist!

i am crazy. why php agi can not receive text from asterisk? sometimes they can ,sometimes they can not. i set the timeout 20000 ,i think it is long enough . who can help me?