Cable-Driven Parallel Robots (CDPRs) form a class of robots well-adapted to large workspaces since they replace rigid links by cables. However, they lack in positioning accuracy. In a previous work, a control law has been proposed to enable a CDPR to perform a profile-following task, based on the data measured by two different and redundant sensors that are fused using the Gradient Projection Method (GPM). However, its robustness had not been assessed yet. This paper analyzes the stability of such a control law in function of the systematic errors on the parameters of the system. Numerical simulations show that the characteristics of the system ensure the stability of the control law in the robot workspace even in the presence of significant errors, provided the initial angle between the surface to follow and the moving-platform is smaller than 11°.