Thank you Brian for your reply.
I didn't mentioned it in the original post but I've put Culling Mode to None already.
I did try out the Double Sided-flag before however, when I looked at it, it seemed to me that it was like the normal rounding like when the picture in on the front of the cylinder. However, I just tried it out on a bigger cylinder and it acually does put in on the inside and at the back of the cylinder with the inverted bend. But it doesn't make a big difference on my project but that's fine. At least it works :-)
Also I've noticed that when I'm trying to apply a picture to a cylinder, the picture get deformed. I need to use the Texture Coordinates to try and rectify it again. Is there like a specific rule to follow to put your pictures back in the right aspect ratio?
#XPression