Q: scan problems

Typically, I recommend using the "Image Capture" application that comes with your Mac insted of installing any software that came with your scanner.  Look in "Applications" for the "Image Capture" application.  Launch it, and your scanner should be available and allow previewing scans, and scanning to whatevever file type your wish (PDF, TIFF, JPG, PNG, etc.).

If your scanner is TWAIN or ISIS compatible then it may also be available for direct capture from applications such as Photoshop Elements or any other photo edit application.

I general I always recommend NOT to install any software that came on a DVD in the box with your scanner, camera, printer, etc..  It's amazing that even the best hardware manufacturers seem to package horrible software with them.  No mater if you have a Mac or Windows operating system, it's nearly always better to just take the hardware out of the box, ignore the instructions, and just plug it using USB.  Then, do a bit of Googling and you will find that both Mac and Windows operating systems have built-in software the it almost always far better than the software that came with your device.  And, by not installing the software the came with the device, you will avoid a significant amount of completely unnecessary "crapware" that would have been installed on your computer.