Foods to avoid for kidney stones?

I’ve never been officially diagnosed with kidney stones or never passed one large enough to hear it hit, but that was my doc’s best guess for pain in the flank. After a recent bout I went to the web to see what foods I should avoid and was startled by what I found. Some sites warned me off what seemed like half my diet (I’m vegetarian), but I settled on the Mayo Clinic’s advice: “Many foods and beverages contain oxalate, but only a few have been shown to increase the amount of oxalate in urine: spinach, rhubarb, nuts, wheat bran.” I’d always eaten a lot of spinach (a whole lot lately, it seemed) and helped myself to a handful of mixed nuts several times a day, so that could have accounted for some recent pain. Even so, I found another study showing that pistachios are very low on the scale, so I can at least satisfy my craving for nuts. (Apparently it’s almonds that are the real villains.)

Does anybody have any knowledge to confirm my suspicion that warnings against everything from black beans to collard greens are just crying wolf? In other words, does high oxalate content in foods necessarily translate to high content in urine?