I'm getting the same shenanigans. According to the thread where they talk about the various G errors it means that it's a problem server side. I've been playing PS since the Beta, and this is the first time I've seen the error crop up but it happened both yesterday and today. *EDIT* Try validating your game files. I dunno if it's gonna work yet (since I'm redownloading files) but according to steam over 500 Planetside files failed to verify. My install is pretty old so that could be what's going on there, but it sounds like that's pretty much the entire game.
You an't supposed to let Steam validate your files. There is a forum thread that says Steam's methodology for this is not appicable with PS2. I'm doing a complete restart now to see if help