For some reason SQLDeveloper started to work a bit weird.
- [END] key was not working
- [ctrl]+[v] wasn't pasting anymore
- [shift]+[cursor left] was not marking anything

i found the solution for this problem on forums.oracle.com

set back your accelorators: Tools -> Preferences -> Accelerators -> Load Preset -> Default
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I just experienced that Oracle SQLDeveloper 1.5.1 has a bug, if you try to export a result as a insert-script.

The delimeters in the VALUE clause are dots instead of commas.

To fix this you have to change your preferences (Tools-Preferences-Database-NLS Parameters). There you set Group Seperator to , (comma) and change the Decimal Seperator to . (dot)
!!! it is important to change the Decimal Seperator as well - it wont work if Group- and Decimal Separator are the same !!!

I don't know why it doesn't work if you change the General Export Parameter to , (comma) but the workaround works just fine.
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