my english is very bad, sorry.
I have try to install Phoca Guestbook and I get any errors:
FTP Install:
Component Install: SQL error or missing or unreadable SQL file. DB function reports no errors
Install from Directory:
Error! Could not find an XML setup file in the package.
Path does not have a valid package
Install from URL (http://joomlacode.org/gf/download/frsre ... v1.3.2.zip):
JFolder::files: Path does not point to a valid folder or the folder has been deleted. /var/www/vhosts/mysite/httpdocs/de/tmp/install_4acb4fb9bafbe
JFolder::folder: Path does not point to a valid folder or the folder has been deleted. /var/www/vhosts/mysite/httpdocs/de/tmp/install_4acb4fb9bafbe
JFolder::files: Path does not point to a valid folder or the folder has been deleted. /var/www/vhosts/mysite/httpdocs/de/tmp/install_4acb4fb9bafbe
Error! Could not find a Joomla! XML setup file in the package.
Warning: array_merge() [function.array-merge]: Argument #1 is not an array in /var/www/vhosts/mysite/httpdocs/de/libraries/joomla/installer/helper.php on line 143
Warning: array_merge() [function.array-merge]: Argument #2 is not an array in /var/www/vhosts/mysite/httpdocs/de/libraries/joomla/installer/helper.php on line 143
Warning: Invalid argument supplied for foreach() in /var/www/vhosts/mysite/httpdocs/de/libraries/joomla/installer/helper.php on line 188
Any Ideas?

Please Help!
Best regards