Form a previous post in respect to this "I noticed a few days ago that The Voice wasn't set to record this week and realised that it was showing as an old episode - I set it to record anyway (separate from the series link). As you said, it was wrongly set as an old episode, which must have been ITV's fault. Glad I spotted it early."
The V6 box is good but in the information provided by a TV company is incorrect then recordings will tend to fail.
You can amend the series link from "New only" to either "Everything" or "New & reruns" which will get around the issue of the episode being wrongly labeled, unless you have recorded the same episode in the last 28 days. The 28 days is important as that is how long the V6 box retains info that something has been previously recorded and show a duplicate in Hiccups.
You can't learn anything from a mistake until you admit that you've made it.
There seemed to be some sort of issue with WWTBAM, I had my series link set to recordings and streaming and mid-week I had two episodes appear as available for streaming that claimed to be Thursday and Friday's episode but when I went to watch one they were actually episodes from earlier in the week, however they then seemed to prevent the actual episodes from recording. I was able to resolve Friday by setting a manual recording and I could watch Thursday's on demand (though I had to go into the full on demand section, trying to view through My Shows would still show the older episode when I tried to play Thursday's) but basically seems like ITV messed up their on demand shows which bust the series link.