I’m hitting the same issue (beta 19), where an exception is thrown when you pull the list for a refresh:
TypeError: Cannot read property 'removeEventListener' of null
at Refresher._mDown (content.js:151)
at Refresher._setListeners (refresher.js:438)
at Refresher.ngOnDestroy (refresher.js:459)
at AbstractChangeDetector.ChangeDetector_FlowRunsPage_0.dehydrateDirectives (viewFactory_FlowRunsPage:190)
at AbstractChangeDetector.dehydrate (abstract_change_detector.js:141)
at AbstractChangeDetector.destroyRecursive (abstract_change_detector.js:158)
at AbstractChangeDetector.destroyRecursive (abstract_change_detector.js:165)
at AppView.destroy (view.js:111)
at AppViewManager_.destroyViewInContainer (view_manager.js:124)
at ViewContainerRef_.remove (view_container_ref.js:116)
Can confirm this issue as well, same error as @boazc. When trying to use the hamburger icon to navigate from the page that has the ion-refresher element, this error will pop up, everything will still work though.