Advertisements I happened to have a Western Digital Red (WD10EFRX) on my desk, so before I used it for its purchased purpose I thought I'd try it in TiVo. Unfortunately it's a 'no boot', so it looks like we can add WD Reds to WD Greens as discs which won't work in TiVo. (And yes I was using an 'approved' adapter.) Did anyone ever find out exactly why some discs work and some don't? The reports seem to suggest that it's discs which use 4kB sectors (rather than 512B) which the TiVo IDE controller can't cope with. Although the WD firmware translates the 4K sector to 512 it appears there is still something the TiVo controller doesn't like. If this really is the cause of the no boot then there is a potential long-term problem here. Since Jan 2011 all new product HDs (well big capacity ones anyway) are supposed to be made with 4K sectors (so-called "Advanced Format"). If 4K sectors aren't going to work in TiVo then we are going to reach the point where we can no longer get new discs for our S1 TiVos. It would be ironic if our S1 TiVos were finally nailed by the lack of HD supply! Thoughts anyone? Is the 4K sector really the reason why some discs work and some don't?