Problem with white font after png export

[Jana26724348uv31]

When exporting as png, the green area is placed over the white writing, although this is in the foreground in Illustrator and when saving the eps. Where is the mistake? never had this problem.. 

[Ton Frederiks]

Can you check if the white type has a blending mode in the Transparency panel?

Also check for Overprint by turning on Overprint Preview.