Nikon D90 is showing auto focus error while shooting other than manual mode

SOURCE: nikon d40 digital camera

So, before i take my d40 to an authorized tech, should i maybe see if the lense needs to be cleaned then? silly question I know. But i really dont want to waste money on sucha petty problem.

SOURCE: Nikon N55 Won't take picture in Auto Focus Mode?

There was a recall on the N55 due to auto focus problems. You can do a google search or nikon.com email the support team and they will send you the paper. This is what I did, I wasn't charged since I had the correct papers. I, however, used one roll of film and my focus went out again! Mine doesn't even work on manual... If you want to try that maybe you will hae better luck than me. GOOD LUCK!

SOURCE: Nikon D80 auto focus

I had the same problem but then I realized the lens was not "in" all the way.  It had not clicked into place when I changed lenses.  This might work for you....it did for me.

SOURCE: i have nikon d40, on continuous mode, auto, it

I don't know what you are doing - mine shoots continuously with no problems. There is nothing to set other than to set the shooting mode.
I have noticed that some memory cards are so slow it doesn't allow continuous mode. I recently replaced mince ith 16G class 6 cards and they work fine.

SOURCE: Why is there a delay?? Nikon D90

Sounds like you turned on Exposure delay mode (menu d10). This is similar to the "locking up the mirror" (or somethign) feature on canons.

YOu only need it when you doing a tripod shot with long exposure and you want to minimise absolutly all possibility of shake from the camera its self. Lifting the SLR mirror will cause small shake. Generally you can turn this off (i've felt it ona few times my accident and been confused for a second)