Please excuse my newbie-ish-ness, but I've been "out of the loop" for a long time in the IT field... I've got a PIX 515 firewall here which was set up (barely) by the person in my position (always blame the guy before you)... basically, I went to Cisco's site to get the "latest" updates for my PIX. First question is: Is there a difference between upgrading your OS and upgrading your PDM? Second newbie question is: WHICH ONE?!?! I currently have v6.0(1) (PDM version is 1.0(1).... I see 6.01ED, 6.1.1ED, 6.1.4GD, and in particular, 6.1.5GD, 6.2.3ED, 6.3.2ED which all have the same exact date stamp. What's GD and ED? Should I stay within my main revision number? (ie: 6.0.x)