Contradiction only without collect gen

Helle there,

I'm currently having a hard time figuring out some odd behaviour.

when I run a test in a certain configuration, specman throws a contradiction and request a rerun with collect gen. When running with collect gen on, the whole test runs flawlessly as it should.

I'm fresh out of ideas after battling the for some time now. The irritating thing is:

when I constrain a struct in two bool flags as true, a method randomly picks one and resets it. 

If I manually reset all of them in the function, everything works as well.
Having both on true also works out fine.

resetting one of them in the method with the code below breaks a list somewhere in a completely different struct of the environment with a contradiction I cannot see. So using the "random resetter" I coded below, Specman goes nuts.

while list_of_desired_errors.count(it == TRUE) > 1
{
    message(FULL,"list_of_desired_errors.size() is still > 1, randomly resetting desired errors");
    var tmp_err_index_list : list of uint;
    tmp_err_index_list.clear();
    for each (err) using index (i) in list_of_desired_errors
    { 
        if err == TRUE
        { 
            tmp_err_index_list.add(i); 
        }; 
    };
    message(FULL,"tmp_err_index_list is: ",tmp_err_index_list);
    var t_uint : uint;
    message(FULL,"t_uint before random assignment is ",t_uint);
    gen t_uint keeping { it in tmp_err_index_list; };
    message(FULL,"t_uint after random assignment is ",t_uint);
    list_of_desired_errors[t_uint] = FALSE;
    message(FULL, "SINGLE_FRAME_ERR resetting error index ",t_uint); };
};

Ideas, anyone?

regards