[Owncloud] Problems with character encoding and umlauts

[Dr. Hirn]

Hi,

some problems with character encoding and umlauts:

Creating a folder/file with umlauts using the webinterface is working,
except the folder/file is named wrong on the filesystem of the server
(e.g. created folder "häuser" with webinterface gets "Häuser" on
filesystem).
But if I create a folder "häuser" directly on the filesystem of the
webserver, OC crashed with the following error:

PHP Fatal error: Uncaught exception 'PDOException' with message
'SQLSTATE[HY000]: General error: 1366 Incorrect string value:
'\xE4user' for column 'name' at row 1' in
C:\inetpub\wwwroot\lib\db.php:598 Stack trace: #0
C:\inetpub\wwwroot\lib\db.php(598): PDOStatement->execute(Array) #1
C:\inetpub\wwwroot\lib\filecache.php(125):
PDOStatementWrapper->execute(Array) #2
C:\inetpub\wwwroot\lib\filecache.php(601):
OC_FileCache::put('/H?user', Array, '') #3
C:\inetpub\wwwroot\lib\filecache.php(551):
OC_FileCache::scanFile('/H?user', '') #4
C:\inetpub\wwwroot\lib\filecache.php(419):
OC_FileCache::scan('/H?user', NULL, 0, '') #5 [internal function]:
OC_FileCache::fileSystemWatcherWrite(Array) #6
C:\inetpub\wwwroot\lib\hook.php(62): call_user_func(Array, Array) #7
C:\inetpub\wwwroot\lib\filecache.php(695):
OC_Hook::emit('OC_Filesystem', 'post_write', Array) #8
C:\inetpub\wwwroot\lib\filecache.php(269):
OC_FileCache::updateFolder('', '') #9
C:\inetpub\wwwroot\lib\files.php(39):
OC_FileCache::getFolderContent('', '', '') #10 C:\inetpub\ww in
C:\inetpub\wwwroot\lib\db.php on line 598

Using IIS7.5 on Windows Server 2008 R2
PHP Version 5.3.16 (x86)
OC Version 4.0.7

Anyone knows the reason, why this happens?

Thx a lot!
Stefan