Install crashes on OVH shared hosting

Hello, I try to install Omeka 1.5 on a shared server from OVH with PHP 5.3, MySQL 5.1. I change db.ini etc. but the installation crashes with the following error message :
Fatal error: Uncaught exception 'Zend_Cache_Exception' with message 'Could not determine temp directory, please specify a cache_dir manually' in /homez.xxx/musiccer/www/omeka/application/libraries/Zend/Cache.php:209 Stack trace: #0 /homez.xxx/musiccer/www/omeka/application/libraries/Zend/Cache/Backend.php(197): Zend_Cache::throwException('Could not deter...') #1 /homez.xxx/musiccer/www/omeka/application/libraries/Zend/Cache/Backend/File.php(123): Zend_Cache_Backend->getTmpDir() #2 /homez.xxx/musiccer/www/omeka/application/libraries/Zend/Cache.php(153): Zend_Cache_Backend_File->__construct(Array) #3 /homez.xxx/musiccer/www/omeka/application/libraries/Zend/Cache.php(94): Zend_Cache::_makeBackend('File', Array, false, false) #4 /homez.xxx/musiccer/www/omeka/application/libraries/Omeka/Core/Resource/Locale.php(31): Zend_Cache::factory('Core', 'File', Array, Array) #5 /homez.xxx/musiccer/www/omeka/application/libraries/Zend/Application/Bootstrap/BootstrapAbstract.php(683): Omeka_Core_Resource_Locale->init() #6 /homez.xxx/music in /homez.xxx/musiccer/www/omeka/application/libraries/Zend/Cache.php on line 209
Can somebody help me I didn't find any soluce in the forum.
Thanks

Sorry about the (extreme) delay. All of your several posts got marked as spam by Akismet, and I only just found them in the spam trap.

As for your problem, you should only see this problem if you don't have read/write access to your server's temporary directory. OVH should be able to look into this for you, but Omeka uses temporary storage for several things, including caching.

Bottom line: Omeka needs to have read and write access to whatever directory is defined as the PHP temporary directory. Your host should be able to set this up correctly for you.