Having trouble with vivitar 383 and nikon d90?

I have a nikon d90 and a vivitar 383.both were compatible and was working perfectly until last month when i put the flash on the d90 the r18 code showed up. My d90 works okay its just when i put the flash on it won't take pics and the r18 pops up… What is r18 and do i need a new flash?

Normally, R18 refers to how many shots you have in a burst.
http://forums.dpreview.com/...e=33383518

But I found some disturbing info about Vivitar 383 flashes and Nikon D90'.s. I'd recommend getting a different flash, if you value your camera.
http://photo.net/nikon-camera-forum/00Sxgm

Trigger voltage is really important.

While the Nikon is said to be able to take higher trigger voltages (unlike canon, which can only stand 6v) there's a limit even with Nikon dSLR cameras.

Call Nikon and ask them ask what the actual trigger voltage limits for your D90 and then use or not use your 383 Vivitar. 800. NIKON-UX

Do you really need a flash at this time? If not save your pennies and see if you can find a good used SB600 for under $200.

r18 refers to the number of shots your cameras buffer can hold until your shooting will slow down waiting to write the image files to your memory card