Illusionism

This is the error the diagnostic tool gave me every time except this time(the time it's scanning for errors)

Test Option: QUICK TEST
Model Number: WDC WD50 00KS-00MNB0
Unit Serial Number: N/A
Firmware Number: 2E07
Capacity: 500.11 GB
SMART Status: Not Available
Test Result: FAIL
Test Error Code: 11-Cable Test::Read diagnostics sector error!
Test Time: 15:34:18, May 01, 2008