Problem with Slide Menu in ACP

Hi. I have a strange problem in may ACP.
I use German lang files and some entries in the ACP Slide Menu do strange things.
If I click on the "-" in the entry IM-Portal the word "Portal diasppears. But if I click for example on the slash in the entry "phpBB-General" this does not appear. Also interesting is that if I switch the window to another browser window and than switch back the text is visible again. And I can mark a text not visible with my mouse and the text is marked. But when I change the selection the text is not displayed. Very strange.
Here an example:
When clicked on the slash (Entry should be named Profil-CP) :
[flash=,:yn1ffhji]http://www.world-of-miniatures.de/bilder/integra/slash1.jpg[/flash:yn1ffhji]
when mark the text the hidden work is displayed:
[flash=,:yn1ffhji]http://www.world-of-miniatures.de/bilder/integra/slash2.jpg[/flash:yn1ffhji]
If I change the entry name and set a name without a "-" in name it works. The amazing thing is that the problem does not appear on every entry including a "-" in name.
Does anyone has any idea what the problem is?
Greetings
Thorsten
I use German lang files and some entries in the ACP Slide Menu do strange things.
If I click on the "-" in the entry IM-Portal the word "Portal diasppears. But if I click for example on the slash in the entry "phpBB-General" this does not appear. Also interesting is that if I switch the window to another browser window and than switch back the text is visible again. And I can mark a text not visible with my mouse and the text is marked. But when I change the selection the text is not displayed. Very strange.
Here an example:
When clicked on the slash (Entry should be named Profil-CP) :
[flash=,:yn1ffhji]http://www.world-of-miniatures.de/bilder/integra/slash1.jpg[/flash:yn1ffhji]
when mark the text the hidden work is displayed:
[flash=,:yn1ffhji]http://www.world-of-miniatures.de/bilder/integra/slash2.jpg[/flash:yn1ffhji]
If I change the entry name and set a name without a "-" in name it works. The amazing thing is that the problem does not appear on every entry including a "-" in name.
Does anyone has any idea what the problem is?
Greetings
Thorsten