Temporary dead pixel in Photoshop CS5

Question

Hello,
I got some strange bug.
There is a white dot appearing on my screen right after I open any file or preferences window.
The dot turn grey if I drag something white under it.
The dot shows itself only when the PS app is active.
Even if I just click on my desktop wallpaper "through" PS making it inactive - the dot disappears.
Activating PS back - returns the dot.
I figured out that it happens when PS switches from integrated to discrete GPU.
Some more strange behavior:
- If I force to use only integrated GPU before starting PS there is no dot
- If I force to use only discrete GPU before starting PS there is no dot
- If I use dual monitor configuration before starting PS there is no dot
- If I unplug second monitor during PS session the dot appears
- If I plug second monitor during PS session the dot doesn't dissapear
- If I reset or delete preferences in PS folder it switches to discrete GPU on launch and there is no dot. But after closing and restarting PS with preferences saved it starts with integrated GPU and switches to discrete on opening file or preferences. And the dot appears.
Tried to ask Adobe Support and Adobe Community. No solution.
Any idea on what's going on and why is it started only now?
No changes to PS preferences or to system were made.
It appeared just during one of PS sessions.
Thanks.
My specs:
Macbook Pro 17 late 2011
2.5 Mhz I7
16 GB RAM
Two drives SSD + HDD
Mac OS X Mavericks 10.9.5.
Adobe Photoshop CS5 12.0 x64

Answer 1

Well, after all I want ot find out what is the root of this bug. Is it a software bug or a hardware malfunction.
It doesn't seem like a hardware malfunction to me, because the dot appears in one exact place.
If it would be some sort of VRAM problem - then it would be in different place each time, because there is a random information allocation in VRAM each time it loads into.
So it looks like a software or driver bug.
The problem is localized and here it is:
- PS CS5 in current situation doesn't switch to discrete GPU during launch
- If something switches graphics to discrete GPU when PS CS5 is already running - the dot appears in one exact place only when PS interface is active.
It could be new file creation, file open, going to PS preferences, or it could be other application that switches GPUs, or manually through deactivating energy saving options in system preferences, or manually through gfxCardStatus application or any other way to switch GPUs when PS CS5 is opened and hasn't switched GPUs during its launch.
Is that's a normal behavior for PS CS5 - not to switch GPUs on launch - I don't know.
I know that if reset preferences on launch or delete it manually - first run of PS CS5 is with GPUs switch during launch. After closing it and opening it next time - it doesn't switch GPUs during launch no more.
So the questions is what is broken now. If PS always before switched GPUs after launch - then it could be some sort of driver or hardware problem.
If the behavior of PS changed somehow and before current situation it switched GPUs always on launch - then it's a PS problem.
Or maybe some sort of other problem, that I don't see yet.
I haven't found any other program, that switch GPUs after launch, so I can't test it.
If you know any - please tell me.
If anyone of you use any versions of PS on dual GPUs macs - please tell me if your PS switches on launch, or after. You can use gxfCardStatus for that kind of check.
Well I'm going to make a clean install of OS and reinstall PS if there will be no other answer.
I'll share the results.
I've already tried to install Mavericks and Updates over current installed OS, reset NVRAM and SMC - no result.