I generally make use of the GPU preview functionality built into InDesign, but recently I've noticed that files keep reverting to 'Preview on CPU'. I can't see any way of preventing this so I'm wondering if it's a bug'.

It's not a speed issue for me so much as a preview issue. Without GPU preview switched on, imported images look way too bright with particularly garish reds. I'm hoping it's a software thing rather than a graphics card on the way out. Any ideas anyone?