Black border around transparent pngs

[rogelioa31881838]

When i export my indesign document to pdf, there is an unwanted black border around the edges of the transparent pngs I placed in. Anyone know what I can do to fix this issue. Below are examples.

I appreciate any help, still learning indesign.

Thank you,

[rob day · Accepted solution]

Open one of the PNGs in Photoshop and zoom in 400%+. It looks like the problem is in the PNGs

[HNS2000]

yeah, no, its an old commonly known but unresolved and annoying indesign bug. 

[alicinki]

Open them in Photoshop but check them on a white background.