Somebody walked over your grave

The phrase in English to describe the shivers down the spine experience that sometimes happens has long amazed me. The phrase is, "somebody walked over your grave". What a wierd phrase and an incredible view of time, how can someone have walked over your grave when you are here and alive? I know that in Polish they say something similar which I understand translates as "Death walked through you", spooky! The similarity of the concept in Polish, being a Slavic language suggests (to me) great antiquity. Does anyone know anything of the phrase's origins, or anything about it?

Here is a previous discussion. www.phrases.org.uk bulletin_board 11 messages 174.html All I know about it is that in southern W.Va. where I grew up, stepping on a grave was taboo. And I have heard people talk about "someone just stepped (or walked) on my grave."