Text in linked PSD not sharp in InDesin

Hey everyone,

I have a mysterios case and hope one of you can help. I design book covers in photoshop (resolution 300 dpi). When I want to create the print PDF, I place the PSD in InDesign and export there (because it can create muuuuch smaller files than Photoshop *g*). Usually this works nicely and I never had a problem before.
Now I have a case where  the font looks blurry and not sharp in InDesign AND in the exported PDF. (I know about the display view settings, they are on high *g*). I exported a PDF with Photoshop for comparison and it is super sharp.

Screenshot from PDF exported with Photoshop (layers not combined, just hitted the export option):

Screenshot PDF exported with InDesign:

Both screenshots were taken on 200% in the PDF files. If you look closely you can see those frizzy edges on the InDesign export and I am totally confused. I must be doing something wrong, but I don't see it. I am a total noob in InDesign, only really use it for creating print PDFs. 

Before anyone asks:
- No, I can't she PSD and INDD files since it is work for a client with licensed stocks in it.
- I can't just send out the PDF created by Photoshop because it is of a hundred MB size and that's just too big (print service will most likely reject it). 

Anyone has a guess?

Thank for your time,
Nadine