Hi,
while trying to install update manage to perform an update from 1.5.21 to 1.5.22, i get the following error message:

"JFile::read: Unable to open file: 'http://www.muze1.de/tmp/gzip4cf5e96e0e8ac'
Unable to read archive

Warning: fopen(http://www.muze1.de/tmp/gzip4cf5e96e0e8ac) [function.fopen]: failed to open stream: HTTP request failed! HTTP/1.1 404 Not Found in /usr/www/users/muzeya/libraries/joomla/filesystem/file.php on line 240"

Any ideas how to solve this? Since i have some saving issues and problems accessing a proper Version of Backend in Firefox(see image attached), the update seems to be a good idea.

Thanks for helping me in advance,
Sebastian