^ All good advice.
Also, having had numerous words & phrases seemingly become inactive for no real reason, you may be tempted to up your minimum bid to re-activate them. I'd leave things for a while if this happens, it amazing how they suddenly re-activate themselves with your existing bids, and then stay active for long peroids after that.
Maybe even delete some inactive words if there are quite a few of them. You'd be surprised how quickly the remaining inactive words then kick back to life!
You can get quite paranoid about why this is happening!!