bulk write error intermittently

[hexsprite]

       "before each" hook: wrappedFunction for "master no longer recurring":
     BulkWriteError: E11000 duplicate key error collection: meteor.lists index: _id_ dup key: { : "lists2xxxxxxxxxxx" }
      at OrderedBulkOperation.handleWriteError (/Users/jbb/.meteor/packages/npm-mongo/.3.2.0.2al8a6.67uk++os+web.browser+web.browser.legacy+web.cordova/npm/node_modules/mongodb/lib/bulk/common.js:1112:11)
      at resultHandler (/Users/jbb/.meteor/packages/npm-mongo/.3.2.0.2al8a6.67uk++os+web.browser+web.browser.legacy+web.cordova/npm/node_modules/mongodb/lib/bulk/common.js:501:23)
      at /Users/jbb/.meteor/packages/npm-mongo/.3.2.0.2al8a6.67uk++os+web.browser+web.browser.legacy+web.cordova/npm/node_modules/mongodb-core/lib/connection/pool.js:397:18
      at _combinedTickCallback (internal/process/next_tick.js:132:7)
      at process._tickDomainCallback (internal/process/next_tick.js:219:9)