why won't my pc "see" the blank dvd in the drive

[2shoes]

i have burnt to dvd before. but it won't "see" a blank dvd. keeps telling me to put one in. It will burn to cd and will read a dvd but not a blank one.

HEEEEEEEEEEEEEEEEELLLLLLLLLLPPPPPPPPPP

well if this makes sense.
I copied something to a dvd on lap top. the pc will read that. but if i put the same make/type blank dvd in it won't read it. or see it. ds reckons it is a dirty lens. but surely then it wouldn't read the written one.

I have tried all kinds of dvd's even splashed out on sony ones

what is the diffence between the 2 plese

i have just noticed that on the drive it has dvd+ on it and I am trying to use dvd - will that be the problem?

all depends on the make and model of the DVD drive.. can you provide this information