Although i wouldn't load any homebrew or apps like multiman when connected to the PSN. I only used it to download the BBC iPlayer / TV on demands apps, the PSN appeared to work fine. This will let you use the PSN, apparently if you play newer games like Blackops 2 you will get banned, so do so at your own risk.
I'm not responsible for your console, just helping you out. This is how i did it, as always do so at your own risk. I recently updated my 3.55 PS3 to Rogero CEX-4.40 v1.03