Slartibartfast

I'm using 4.1.8 Two plates next to each other, they are in alignment. But when I move one of the pieces over another, it shifts slightly and greys out. It will only become aligned (green) when rotated a full 360 degs. When rotated 180 deg, it looks like this! I found a solution... When I place two plates in alignment next to each other, like the first picture, then, I can place a plate at 90 deg, with the help of the (red) piece, but it only works if I connect the blue plate on the red plate. Then I can remove the red plate and I have the two plates joined at 90 degs! I do have 4.1.8 running on Wine (Linux) working fine and bricks placed over each other do snap to alignment. This is a Windows install. I know its weird, and thanks for helping. I might just wait until I get a newer computer with a better graphics card. Thanks Slarti.

Hi All, Okay, I've loaded LDD on an older computer, updated the graphic card drivers. Its a bit slow, but works. When I place a 2x6 Plate, then place another 2x6 Plate, but rotate it one rotation (with a left or right arrow), it rotates, but not 90 degrees, but about 87 degrees and I can't place it on top of the first placed plate. Then next rotation will then fit. Has any one seen this before? Or should I wait until upgrade my computer? Thanks Slarti...