Mavericks is Acting Extremely Erratic

To help determine the possible causes of this behaviour read the following. None of what follows is intended to fix anything, but it will provide the additional information required to advance troubleshooting:

Boot OS X Recovery by holding ⌘ and r (two fingers) while you start your Mac. At the Mac OS X Utilities screen, select Disk Utility. Select your startup volume (usually named "Macintosh HD") and click the Repair Disk button. Describe any errors it reports in red.

When it finishes restart your Mac and test again for operation. If it's still not behaving as you expect it should, please post the results of EtreCheck in accordance with the following instructions:

Apple Support Communities contributor etresoft wrote a very useful app to quickly gather certain system information that may help point to a cause of this problem. Go to his website, download and run EtreCheck:

http://www.etresoft.com/etrecheck

Etrecheck will be in your Downloads folder. Open it from there. You may see the following dialog box:

Click Open - etresoft contributes to this forum frequently and can be considered a trustworthy developer.

It will take a moment to run as it collects its data.

Copy and paste its output in a reply.

Do not be concerned about anything that says "Problem" or “failed” or anything else that may appear in red.

EtreCheck was designed to remove any personal information (such as your computer's name and serial numbers) but if you see anything that looks like an email address or any other personal information that should not be divulged to others, please delete or obscure that information when you post the reply.

When you are finished with EtreCheck, quit the program. It occupies very little space, and you can keep it or drag it to the Trash as you wish.

After completing the above please determine if the problems also occur in "Safe Mode":

• Safe Mode or "Safe Boot" is a troubleshooting mode that bypasses all third party system extensions and loads only required system components. Read about it: Starting up in Safe Mode
• You must disable FileVault before you can start your Mac in Safe Mode.
• Starting your Mac in Safe Mode will take longer than usual, graphics will not render smoothly, audio is disabled on some Macs, and some programs (iTunes for example) may not work at all.
• Merely starting your Mac in Safe Mode is not intended to resolve the problem, it's to observe its performance without certain additional components.
• To end Safe Mode restart your Mac normally. Shutdown will take longer as well.

Perhaps you should do a bit more investiagation before assuming it is any known problem. I wrote a little diagnostic program to help show what might be causing these problems. Download EtreCheck from http://www.etresoft.com/etrecheck, run it, and paste the results here.

Some of the results I have seen recently from people reporting things like "erratic scrolling" in Mavericks have included the full list of all known "red flag" system extensions known to cause problems. I think this is one of the reasons Apple developed the Mac App Store. There is just a stagging amount of really, really bad software installed out there. This stuff was junk when it was released 4 years ago and it sure doesn't run any better in Mavericks. Usually, it runs much, much worse and people just assume that Mavericks is to blame.

Disclaimer: Although EtreCheck is free, there are other links on my site that could give me some form of compensation, financial or otherwise.

PACE is an anti-piracy app that may have been required for Avid Pro Tools. Its name implies that it is outdated. Check with Avid or whatever software you may have that required PACE to determine whether or not it remains required, and what they intend to do about it if it is.

As of a few days ago Adobe Creative Cloud was not compatible with Mavericks. Adobe may have fixed it since then, or not. There are a number of other system modifications present that may be responsible for this problem as well.

There is just a stagging amount of really, really bad software installed out there.

There is, and the overwhelming majority of problems reported on this site have always been attributable to that factor. The relative proportion of problems caused by junk software remains unchanged with Mavericks.

Apple's direction has been tending toward a system that is likely to make it impossible to modify a Mac with junk software. The Mac App Store and Gatekeeper are only the beginning. In future OS X iterations, it may yet be possible to install whatever you want, junk or otherwise, but it is likely to require a degree of inconvenience or expense for the privilege. Apple understands that its market expects dependability, doesn't care how that goal is achieved, and a generation of computer users that comprehend the nature of operating system modifications and software in general are dying off. So enjoy the ability to install such things while it lasts. End of speculation.