Intermittent Mouse Pointer Problems - Please Help?

Hi there, I'm Carlos, and I've been experiencing a variety of mouse pointer-related problems lately, all of which occur intermittently, and usually simultaneously as well.

I am experiencing these problems as I type to you; I am a graphic designer, and these glitches began as mostly negligible grievances, but now occur at such a frequency, and such lengths that it's actually bogging down my work productivity considerably, and frustrating me more and more during each instance. The problems include:

1. Mouse Pointer Not Acknowledging Text Or Links

- Usually, when one hovers over a text box or link, the mouse pointer would change into the "I" typing cursor, or the 'glove/ hand' cursor. During problematic instances, my cursor would remain in its standard 'black arrow' form, & not change despite what its being used for.

2. Mouse Pointer Does Not Right Click

- During problematic instances, clicking the right-mouse button does not summon the usual list of options.

3. Mouse Pointer Does Not Highlight Menu/ List Options

- Standardly, scrolling through a list of menu options causes the hovered-upon option to be highlighted in blue. During problematic instances, my pointer scrolls through menu/ list options not highlighting anything. Then, if I tried clicking on an option on the list, sometimes they would work as normal, whereas other times, they'd remain unresponsive.

4. Glitchy Mouse/ Dock Interaction
- Normally, hovering my pointer over the dock causes its icons to magnify, causing a 'wave' effect as I move my pointer from icon through icon. During problematic instances, hovering my pointer over an icon would magnify the icons over that area, but leave the rest of the dock 'frozen', and unmagnifiable. The dock icons still function when clicked (they bounce and launch their respective applications), but do not react with my pointer the way they should.

5. Dragging Or Highlighting Items Causes Weird Display Glitches
- Sometimes I would save an image from my browser, onto my desktop by dragging it straight through. During problematic instances, the image usually behaves as it normally would when it's being dragged from the browser, but then glitches; turning into a frozen watermark once I drop it onto my desktop. Sometimes a similar problem would occur during standard drag-n'-drop instances of files and folders.

6. Mouse Pointer Randomly Displaces Itself To Bottom Of Screen (Mouse-Jumping)
- Most irritatingly, my mouse pointer tends to randomly jump towards somewhere on the bottom half of my screen, often causing me to accidentally launch applications on my dock, or just clicking random links I hadn't meant to.

What I've Tried:

- I've tried relaunching any app that's began experiencing the pointer-related problems to no avail. When the glitches occur, they usually do so over my entire operating system, not just one application. I've relaunched using both the standard CMD+Q action, or by ending the process via activity monitor.

- I've tried restarting my iMac - this usually fixes the problem for a meantime, but does not stop them from reoccuring in future.
- I've tried unplugging, then replugging my mouse, and using different mice/ mouses to no effect. The pointer problems also affect my WACOM tablet.
- I've tried looking through many forums; most people seem to have 1 or 2 of my problems, and have found solutions to those problems exclusively whether using software, or hardware solutions, none of which have worked for me.

- I've tried exploring Mouse Settings and Universal Access Settings as posters on forums have suggested to no avail.

- I've tried to determine whether or not my mouse buttons could be stuck/ jammed, but they seem fine.

- Of course I've also tried banging my mouse in frustration, but that could hardly have been expected to work.

- What I'm going to try next is install an Apple Software Update through the 'Software Update' function. Hopefully it does something to remedy this.

I use:

- A 27", late 2009 iMac
- Intel Core 2 Duo
- OS X version 10.7.5 (11G63b)
- ATI Radeon HD

- Logitech Optical Mice (USB connection)
- WACOM Tablet
- I do NOT use or have a trackpad

If anyone here might be able to help, I'd be very grateful. I bought my Mac to streamline & professionalize my workflow, & these glitches are really doing a number on my productivity. 😟 Thank you to anyone who might have any helpful advice, and thanks for reading.
,Carlos