get it lots but its an easy fix.
Assuming that you use firefox as most people do nowdays (well, either that or chrome but I'll talk you through FF)
Tools
Options
Privacy & Security
Cookies & site data
Manage Data
In the search box that pops up type the site name
Select it
Press remove shown
Save changes
remove
Thats it, you're done and the site will work again
HTH
Shamus.