Security Test and Datasource Loops

Hi All ,
it's a great tool you've done here , i am using now the Trial soapUI Pro

i am having a problem that i don't know if its a bug or it's just not supported ,
the issue is : i have a WS that i need to check for security issues But i have one parameter that is unique with special value can't be repeated " Reqid" so i need all to be tested except this value i need it to be filled from a Datasource

steps I've made is :
1- created Datasource and loop and inserted my request between them [ at functional it works great ] Read , execute , Loop , Read , execute ,....
2- I added this TC to Security test [ it came with its Datasource and loop ] however when i execute now the scan reads the data source [ just once ] then execute all the attacks for selected parameters Except the unique parameter it gets it from datasource

the issue now is , it gets the 1st parameter only in Datasource and execute all attacks [ each attach in a request ] with the 1st parameter witch will be invalid after 1st request

what i need is each request to read a new value from the data source "Reqid" and an attack other parameters from soupui saved attacks .

Thanks for giving the chance to Ask