"Problem detected with audio clock. Check that your clock source and sample.........

[ASD15]

"Problem detected with audio clock. Check that your clock source and sample rate are correct."

I just bought Mbox2 with Pro Tools LE. I'm fairly sure that I've installed everything correctly and everything seems to be hooked up right. So I hook up the Mbox2 and my guitar/headphones and press record, but when I try to start the recording session by pressing play, I get that error. I've already tried changing around the sample rates and clock sources and nothing seems to be working.

I'm using Windows Vista Home Premium (with Service Pack 2) on a HP Compaq Presario CQ60 Notebook PC. My processor is an AMD Athlon Dual-Core QL-62 2.00 GHz. I have 2.00 GB of RAM memory. My system is 32-bit.

I had known that Pro Tools has not be proven to work right all the time on Vista, but my cousin has the same operating system with similar specs and it's been working fine for him for months. He suggested that I might have to switch back to XP. Can anyone help?