I am experiencing this right now and it's horrible. It seems the pine nuts causing this are from China and Russia and I found this comment on another forum:

"This is "old news". Where I work we have been aware of this issue, intermittently, for over a year. I have not been directly involved, but to the best of my understanding, the pine nuts in question came out of the Sino-Russian border and they were presumed "econmically adulturated" although I was never told with what- but if I had to take an educated guess it was some kind of preservative. You should have no problem with very fresh pine nuts coming out of Western Europe or North America. If you r anyone you know does have an incident with pine nut mouth you should immediatly notify the store where you purchased the product and then call the FDA because the USDA and FDA have an open investigation into this issue. Also, in these types of cases it is always extremely helpful to have a sample for forensic analysis. "

[link to donrockwell.com]