Okay you may need to manually delete the cache files.
It does happen to some.
FTP to your site goto the cache folder delete all files except for the index htm or index.html file.
Then rebuild the cache from the control panel again.
The rebuild will force all the files to be re-created.
Then see if it gets stuck again.
What function in CP does this as I deleted all but 2 index files and did you clear cache function but now all islands are missing ?
