the google cache for my page is wrong... it displays a different website and i thought it would change when google updated the other site but it didnt...

for example:

sitea is cached for sitea and siteb

site b is not cached.

so when i search site:siteb

it shows a list of cached webpages and the index is correct

but when im on siteb and click veiw cached in the google toolbar it shows up as site a?
this worries me because i need sitea to be sitea and site be to be siteb...

any ideas of what the problem could be? thank you in advance for any thoughts you may have on the problem.