Happened to SWIM tbh, The only solution is to throw out all affected foodstuffs, and clean the freezer from top to bottom.
all I can say is make sure that your freeze precips are DEFINATELY sealed, tightly, in something like a mason jar as acolon_5 said,
and definatley don't just put glasses of naptha sitting uncovered, or even lightly with tinfoil, in your freezer.
as for burping up the taste? never experienced that: but it did stick a horrible aftertaste (which you get on exhalation; like tasting a wine)