My windows vista sidebar gadgets had been working fine up unitl one time i started the computer, after i signed in the gadgets did not appear some gadgets were just a small white or black box (eg the clock) with a cross appearing when the mouse was moved over them. Im not realy sure what happened and i would quite like to have my gadgets back. Could anyone help?

just restart or system restore 24 hours

those side bars are the worst things you can have, yours is an example

That occasionally happens to me. i just click and drag the gadget onto the desktop, let it go, then drag it back onto the side bar. It usually works, although sometimes you need to restart the computer.