The pins on the Stackable Header, available as an extra, are a little wide to suit the Digispark headers.
The problem is easily fixed by rotating each leg approx 90 degrees. 60 degrees as suggested by bjh.
After they are soldered in, you can bend them by grabbing the pin approx 3-4mm down from the board, and twisting gently.
On the plus side they are more robust than some of the other types supplied for Arduino shields.....
Cheers
Mark