That always happens to me when my Cache gets really full,
heres what to do,
In Internet-Explorer:
Go to the ''tools'' menu at the top web broswer
Select ''Internet Options''
Click to delete temporary internet files.
If you use Firefox::
Go to the 'tools' menu at the top web broswer
Select 'options'
Select 'privacy'
Click the Clear button for cache
Hope this helps.