Well i am not aware about your VO. But it will be updated with in 20-25 days max.
About your PO Box. ...it depends on your country postal system. Like in india if one write PinCode : 123456 or without Pincode ...it does not make any difference.
So if it really matters in your case...then inform your VO after your e-cas changed to RBVO.
I received my PER on 21st of march, 20011. Still no RBVO update. For the first time today, i can see my address on e-cas. But when they write my p.o.box number they just wrote the number only; It doesn't say " P.O.Box No. 31359 ". It reads only "31359" with the name of city and country. Should I notify them for this ? Please I strongly need your feedback.