Why does the keyboard focus keep switching to the menu bar?

You've likely pressed and released Alt, which has activated the menu bar.

I don't really know why more people don't see this issue.  Perhaps it has to do with how folks use their keyboards.  I never see the problem, but then I know to keep off the Alt key unless I'm modifying some operation.

-Noel

ISTM that more and more apps are hiding the menu bar as the default, and new users are expected to work out that they need to hit the Alt key to make menu items visible.  Mind you, as a recently new user of Windows 8, I've had to work a few things out for myself as well.

Alt doesn't really "unhide" the menu bar (speaking of Photoshop), but it's always been the introducer of keyboard operations for "keyboard accessbility" - i.e., operation of Windows applications without mouse.

Alt causes little underlines to show up under the key characters of menu items, and prepares the system for the next character being typed to open a menu - so for example you press something like 'e' and the Edit menu pulls down.  Now you use an arrow key to move to the next item, or maybe a single character that's associated with one of the menu entries.

Photoshop's goals for using modifier keys kind of conflict with this.  They've apparently tried to reach a balance where using the Alt key to modify some operation cancels the introduction of the next menu item. 

But I don't think it's possible to be perfect at that, especially for example if the user presses Alt, decides not to do the operation he was thinking about doing (e.g., zooming out), then just releases the key.  Another factor might be the habits people get into for choosing tools.

As a contrast, one person might not press the Alt key until they're sure they're going to do something with it (e.g., zoom out), and that same person might only choose tools from the Tools panel by clicking on them.  Another person might press the Alt key sometimes, but then stop before doing the operation it modifies.  That same person might be in the habit of choosing tools by their letter (e.g., E for eraser).  It's clear to see how the first person might never get into a condition where the menu introducer key (Alt) leaves them in a state where a menu opens inadvertently, while the latter might see it regularly.

As far as why Photoshop might get into a mode where the menu introduction occurs when you HAVEN'T pressed the Alt key, I don't know; I certainly haven't seen that reported much if at all here on the forum.

-Noel

Hey there tunghoy ... have you found the solution to your problem? I have the same issue and after reading these posts I think I understand whats going on. I use my alt key while I zooming with my mouse wheel ... thats why the alt key keeps selecting

the menus.

I have the same issue with the V keystroke for move. I will being to move a layer and all the sudden the focus will change to the menu. I am not hitting alt. Is this fixable?

Same thing happened to me and I did search through these forums.

I found out that I had an app running in the background that had hotkeys shortcut enabled. I turned off the hotkeys and it works fine now. Problem was on CC2015 Photoshop.

Please check if you have any app running in the background, such as a screen grab utility.

Thanks Roesti for tip, I think i found the culprit.

As with some of the other users here I was having the same issues with hotkeys appearing to be pressing alt at the same time, and yes Noel, I know 'not to press alt'.. so thanks for your less than helpful comment..

Anyhoo, I was running display fusion (multi monitor software) and it seemed to be messing with my hotkeys - I know it has a huge amount of hotkey hooks it uses. So I ended the process and the problem immediately stopped. I will have to set adobe software as an exception in the settings.

Thanks again

Try minimizing and then reopening Photoshop. Worked for me!