to long? this just happens when you do a long exposure its the CCD over heating there is nothing wrong or bad about it. just edit it out or use a program like Lightroom which removes hot pixels automatically.
400 isn't too high but when you're doing long exposures you'll really benefit from using the lowest iso possible. i usually let the shutter hang open longer or drop the aperture a bit if i'm wanting more light. the worst thing you can do is bump up the iso if you're trying to brighten up a long exposure. i usually leave the iso at 100 and adjust accordingly from there.
"You only have 6 posts, so you should probably go with the griffon, seeing that someone with such low posts would never need anything over 12 din. I mean I have just over 100 posts and ski 14 din binders, so u would have to work your way up, smell what I'm steppin' in.......... " - theNUTZ