I found this link to the prodigy manual: http://cdn.billiger.com/dynimg/QdmrR5VHzn0kdPGERyty6ft4H9rycHjeBa9LTdXG2DAcV-IyjDxd3zuouLtvo4IZG3AU0BfWeEA7sTQSQAkHNU/Schnellstartanleitung.pdf
if you look in there you'll see that all the screws all labeled for specific uses..
Thumbscrews M3: x4 (for ODD)
Standard Screw 6-32 Hex: x 4 (For PSU)
Standard Screw 6-32*6mm Flat: x 7 (For MB & ODD Bay Screw Brackets)
Standard Screw 6-32*10mm round: x 5 (For securing HDD trays)
Standard Screw M3*5mm Round: x 12 (For 2.5" SSD & ODD)
the ones you used were either for the Optical Disk Drive.. or the Power Supply.. I'm not entirely sure man! I'm figuring this out right now. One year.. after you built your computer.
Just wanted to post that manual link for people goin through it for the first time like me.