My AllExperts Mac OSX Q&A http://en.allexperts.com/q/Macintosh-OS-1063/indexExp_16292.htm
My PC is mac mini, OS X.4.11.
An odd anomaly has begun when I boot up the PC.
All icons on desktop have enlargened to max size, the text within
is enormous, folders the same. If I shut down and restart, 4 or 5 times, 3the problem vanishes, only to return again.
SIMULTANEOUSLY, my apple pro optical mouse has begun to
be quirky, the cursor leaps and jumps around, settles down, then
gets wacky again for 2 or 3 minutes. I have never seen this quirkiness before and don't know how to troubleshoot it !
Running a monthly maintenance utility is one of my main recommendations - Mac or Windows.
On Mac, I prefer AppleJack. It runs in Single User Mode (white text on a black screen). This allows it to run fsck (file system check) the same utility that Safe Mode runs at atartup and Disk Utility runs on hard drives other than the current startup drive.
AppleJack review http://www.macworld.com/article/135377/2008/09/applejack15.html
AppleJack download http://applejack.sourceforge.net/
Another option is YASU (yet another system utility)
The size of the Finder Desktop Folders is set in the Desktop View Options under View menu
If you change the settings to your preference without any other programs running and no Finder Windows open and restart the Mac it may fix it.
OR delete the com.apple.desktop.plist in your USER > LIBRARY > PREFERENCES folder
The flaky mouse is most likely a dying battery.
Second mostly likely a less than ideal surface - try a manila folder.
Third most likely, the mouse needs replacing.
Fourth, the lense on the bottom needs cleaning.
The Computer Guy, Seattle
Ballard, Queen Anne, Fremont, Magnolia