Getting Partial Response in FLEXJSON serializer - flexjson

Question

I am using the Rest full web-service in one of my project .
As per my business module I should not give complete object module in the json response. To achieve that I am using flex JSON serializer. Wit flex json I am able to serialize the object and give only selected attribute the response.
The Problem here is when I am testing my services using JMETER tool some time I am getting partial Response in the REST full web-service.
EX: My Object Module is as below
EMployee:
name
age
address
salary
without Jmeter the response is
[ {
"name":"martin",
"age":30,
"address":"america",
"salary":2323
} ,
{
"name":"dddd",
"age":30,
"address":"gggg",
"salary":2323
}
]
When I run same service with Jmeter with 50 user in 10 sec 1000 loop I am getting following response
[ {
"name":"martin",
"age":30
} ,
{
"name":"dddd",
"age":30,
"address":"gggg",
"salary":2323
}
]
you can see in the above respons. The first employee details coming only name and age. address and salary is ignored.
Please anyone help me in that to resolve this problem
Thanks,
Lokesh Sajjan