Ok! I checked the OCS again before a while and the assignment....were right there!!
I don't know what happened so i think that maybe had to do with some loging in and out or some time-passing...!?!
Could it be?
Just for the record: I work with a testbed OCS installation so when i make a review request i usually choose "skip email" and then i manually select "WILL DO THE REVIEW" to confirm the assignment. I have tried it many times and always worked till now.