screensaver slideshow

Hello All, I have my screen saver configured to slideshow, and the preview
works fine, but it never comes in after the specified amount of minutes of
standby, no matter the setting. I have Windows Vista Home Edition, with SP1
and all updates included. I do have a wireless mouse and I ran the option
suggested by some one about this conflict, and it worked for a while, but it
is not working anymore.
Any ideas? Thank you, Adriana