Well, now I'm a bit concerned about updating my 1.5.1 Industrial pack. I've been out for a week with medical problems, and in that time frame several of the mods I want to include have either updated, or have finally gotten 1.5.1 releases. Up until now, things have been smooth, mostly because I re-order block IDs by default and have done it enough I know where the potential problems lie. But all the issues that are being brought up here worry me a bit, as they seem to be in the new versions I don't have yet.