Responding to initial customer and developer feedback, Apple Inc. investigated reports concerning data loss and corruption in Mac OS 8.5, and updated the Mac OS, releasing Mac OS 8.5.1 on December 7, 1998. Inefficiencies in Drive Setup, memory leaks in AppleScript and memory problems in the file system, a Mac OS Extended format corruption issue, problems concerning the use of many third party ADB devices, and communications troubles through Internet proxy firewalls for Sherlock, were all resolved with this update. Apple also chose to include some new Sherlock plug-ins.