I was notified today of an upgrade for Parallels for Mac Desktop (13.13.1 (43365)), and after reading the change log, I installed it. I am running software on a Windows XP SP-3 virtual machine, and this update introduced a huge delay between pressing the Tab key on my keyboard (wired, not Bluetooth) and the cursor's moving to the next field in our software. Most of my job involves entering data into our company's software suite and Microsoft Excel, and I press the Tab key thousands of times a day. Is there a fix for this? What could have caused it? I am cautious about upgrades, but of all the possible bugs that I could have contemplated, this is from left field. ***If there is a way to downgrade to the previous version of Parallels, please tell me how to do it.*** I would do it immediately, as this has very significantly slowed down my workflow since I now have to watch the screen to visually confirm that the data is showing up in the correct fields, not to mention waiting to see if the cursor has even moved to the next field, yet.