How to configure or increase request buffer size when TestComplete runs SoapUI Tests as Test item

Hi. 

we're using TestComplete 10 and just trying to run REST api test created from SoapUI (5.2.0) tests as a Test Item.

SoauUI test itself is working without any problem, but when we run it from TestComplete, it seems that TestComplete cut off 'Post QueryString' so that means Incorrect Request is always sent to....

this only happens if QueryString is quite long (our case is Content-Length: [63202] ). when we post request which has a simple querystring, it works..

so I suspicious there might be sort of limit on request buffer???? especially when we run SoapUI files by TestComplete?

is it true? or any other way to increase or configure it? 

Thanks.

YB