I just recently ran into the problem of defective mulitmeter probes. I purchased a Fluke 87V couple years back but haven't really used it much since i have a bench top unit I mainly use. Used it to test some low ohm resistors and discovered that that my readings were >2ohms off. Turns out the resistance on one of the fluke leads was the culprit. I isolated it down to the probe itself. I carefully cut away the molded plastic to expose where the probe tip is connected to the lead wire, hoping to isolate where the resistance was coming from. Of course, after exposing the wire/tip junction, the resistance went away and I really didn't learn the exact cause. The wire/tip connection is crimp only, no solder. Replaced them with the Probemaster probes which have a combination crimp/solder connection.