parsing xml files including German cause an issue(php5.3 and php5.2)

[bluefivecn]

Hello,
As you can see, my xml file includes some German charaters as following:

In php5.4, it's working well, but in php5.3 and php5.2 an error happened when creating the SimpleXMLElement.

I looked into this issue, this has something to do with the ENT_XML1 option in htmlentities. PHP added ENT_XML1 from php5.4, that's why it's working well in php5.4.
But in php5.3, when creating SimpleXMLElement with the string "ä" instead of "ä", it failed.
I am not sure how to fix this, any help will be appreciated.

Thanks!!!