Shooting mouse cursor beyond intended straight line between two points.

Question

I copied this forum question from Lightroom, and I hope this is ok because I did not know how to express the problem I am experiencing:
"The photoshop brush tool interprets shift-click as a brush stroke that connects the previous brush mouse-up position with the current mouse-down (the shift-click) as a straight line stroke.
[My experience is that every so often, maybe every three or four "shift-clicks" to get my mouse to create a straight line to my next placed mouse position, the Mouse goes Wild, and shoots way beyond my intended next position, and depending on how zoomed in on the image i am, I frequently loose my place where I had been working.  It becomes quite frustrating as this is a very frequent occurrence.  I have heard others with this version CS3 as well as CS2 having the same "shooting Cursor" which is accompanied by some cursing of my own.  As said below, Time savings is the reason for this technique.  If this problem has been dealt with already, I am sorry to have clogged up the forum, but please re-direct me with the key words to find that thread.  How do I cause this shooting cursor to stay within my mouse placement?]
I find this a HUGE time-saver in creating masks as it doesn't require that I have a steady hand. I'm frustrated that LR does not offer the same capability. This feature would complement the auto-mask feature (kinda works). I could create a mask in a fraction of the time if LR included this feature.
Another irritation of occurrence is when setting lines from the rulers, the image will suddenly zoom in by a small amount.  In other words, there are several areas where the software seems to have a mind of it's own, and behaves in an erratic fashion not at all related to the intended action and result.
I am operating a Mac 10.5.7
Model Identifier: MacPro3,1
  Processor Name: Quad-Core Intel Xeon
  Processor Speed: 2.8 GHz
  Number Of Processors: 2
  Total Number Of Cores: 8
  L2 Cache (per processor): 12 MB
  Memory: 2 GB
  Bus Speed: 1.6 GHz
ATI Radeon HD 2600 XT:
2x2.8 GHZ Quad-Core Intel Xeon
2 GB 800 MHz DDR2 FB-DIMM

Answer 1

Thanks for your quick reply.  I am attaching screen shots of my 
current mouse setting, and a graphic of how the behavior is 
demonstrated.  The image is one in which quick mask is being used to 
create a selection, and I am using the paint brush and find it easier 
to use the brush with the technique of clicking the brush at one point 
then holding the shift key while I click the brush at the desired next 
point which should allow the brush to paint a straight line between 
the two points.  The technique works for 3 or 4 clicks, when at the 
next click, it is as if it was just shot clean out of the realm of the 
desired area.  It is almost funny, except that this is a technique I 
find most useful and frequently helpful, and is not confined to the 
paint brush, but the eraser as well.  This does occur also with my 
computer at work, a pc, and a Microsoft mouse.  I have been using 
Photoshop for 12 years, and this problem did not start until I started 
using CS3 extended.  We have upgraded two HP pcs at work to CS4 
extended, and each uses a different mouse, and both exhibit the same 
behavior as experienced by other persons working at those stations, 
and while using Photoshop.
I do hope you could look into this a bit further, Mark, as my 
explanation of the problem may not be clearly presented for you to 
fully understand just what I am experiencing.
Thank you for your help.
Fred