Apple has just updated OS X to version 10.9.4 with fixes for security, compatibility, and stability, as well as Safari version 7.0.5. This update fixes a number of issues, including a problem that kept some Macs from automatically connecting to Wi-Fi networks. Waking your computer from sleep is now also more reliable.
Users can download the update from the Mac App Store. Simply go to the Downlads section and hit Update or Update All. More information can be found on Apple's Support website. Come back after you update and tell us if you notice any improvements in OS X 10.9.4 below in the comments.