Vugen Replay issues in Cognos 10

Hi,

We have a business process to open the report in cognos 10, recorded the script using LR 12 version and did all correlation. While replaying it, the correlated value cv.actionstate value captures intermittently in replay log. 

i.e. The value sometimes displays in few runs and sometimes it doesn't, just a blank value for cv.actionstate in server response.

Auto Correlated as:

web_reg_save_param_ex(

               "ParamName=cv.actionstate",

               "LB=\"cv.actionstate\": \"',

                "RB=\"",

                SEARCH_FILTERS,

               "Scope=Body",

                LAST );

Is this is the commom issue related to cognos10 or any configuration/setting need to be done to overcome this issue....?

PC and LR details:

Win 7 OS, RAM 8GB, LR 12, web (http/html) protocol, recording mode: URL

Thanks,

Prasanna