i have also an issue with Pretty / Clean URLs PRO module from mypresta.
I tried to contact vekia, in July, i have a respond from him with a workaround that it didn't work and i am still waiting for a solution.
If you have a problem with a module, the support from vekia is unsure and that is of course a big problem. I have bought 4 modules and updated them one time but when i needed support i didn't have a proper support from mypresta.