I also tried disabling all of the mods except for the official patch.
In that case the corruption Bllasae speaks of is most likely in your save game. You can test this by starting a brand-new test character and taking a new amulet to Jauffrey.If he takes the amulet, there's no point in re-installing: your current install is just fine.
I've done the MQ with all those mods except for Creeper Jones and HmnsOblivionScriptOptimization. My money is on HmnsOblivionScriptOptimization as being the culprit. If it were me, I'd disable that mod, start a test character, COC to Weynon Priory after receiving the amulet and see if Jauffrey will now accept the amulet.