software/keyboard issues. After uploading Snow Leopard - 03/10/15 - I am no longer able to adjust the speaker volume on my iMac. All other keyboard functions seem fine. But when I press the speaker key - F12, the Dashboard pops up.

I used Leopard to erase my hard drive, then discovered I couldn't download the latest Adobe Flash without first upgrading to Snow Leopard, which I did, after purchasing, receiving (03/10/15), and installing last night. Now, even though I can type with the keyboard, I am unable to adjust my speaker volume using the designated speaker keys....F10, F11 & F12. When I push those keys the Dashboard pops up, but depressing these keys does not affect speaker volume, up, down, etc. Again......typing keys seem unaffected.