Disturbance and Sharp edges when using brush tool.

Question

Following are the specs:
Photoshop Version     : CS5 Trial, CS4 extended
OS                            : Windows 7 Ultimate 32 bits.
RAM                         : 4 GB DDR3 (3 GB Usable)
Video Card                : XFX GeForce GT 240 1GB DDR5
Free Disk Space        : 14 GB Free in C:/ Drive (Primary storage drive for cache levels)
Monitor                     : Samsung Myst Eco 20 inch widescreen LCD.
Well there is no error in my photoshop except when i use the brush tool the brushing looks like its full of dust speckles. Like i am using scatter. When i zoom in it looks weirder. I thought it will be my monitor (i raised a discussion about calibaration of my monitor 3 or 4 months ago when i bought it), but when i export it as .png or .jpeg the image looks perfect i.e. without any scatter. While in Photoshop it looks like i am brushing using some kind of amoeba. I reinstalled cs4 countless times but to no avail. Checked all my brush settings, everything's normal. I downloaded CS5 Trial and checked in it and the photoshop has the same problem. Here are the Print Screen and Exported JPEG's from both CS4 and CS5. And i just wanted to point out that the brush tool works in all other software's so here is Corel Painter PRT SCR too.: What can be causing such weird reactions? I tried enabling/disabling OpenGL rendering, changed cache directories, reduced history/increased history. I messed with everything the performance tab has to offer in preferences, but to no avail. Please Help me, i need to paint lots of thing and with brushes looking like this, it doesnt help at all.
CS5 PRT_SCR
CS5 exported PNG
CS4 PRT_SCR
CS4 exported PNG
Corel Painter PRT_SCR

Answer 1

Wow, I would have bet money that would have made a difference.  You might want to add the monitor profile you had back in.
The only other thing I can imagine is that somehow your display is set to an oddball color depth...
Check this:
Right-click on the desktop and choose Screen Resolution.
In the Screen Resolution dialog, click the Advanced Settings link.
In the monitor properties dialog that comes up, in the Adapter tab click the [ List All Modes ]  button.
Is the current (highlighted) mode a True Color mode?
Beyond this I can't begin to imagine what could be up with your display.
Do you see the same kind of graininess in other aspects of the Photoshop display - for example gradients rendered with the Gradient tool?
-Noel