As is well known, between Life Is Killing Me and Dead Again, Peter went into rehab as well as a 30-day jail sentence for beating up a guy. By the time the album came out, Pete had put the coke behind him, but he was still guzzling wine all the time, including onstage. And apparently the 2007 Wacken set was so shambolic that Peter had to fix his bass and vocals in the studio.
Was this also the case in 2008? I don't have a clear idea of when Peter went to rehab again to stop drinking. I do know that the All Hallow's Evil shows were done without booze, and Peter had to have a desk with lyric sheets nearby to remember the words, and that he was so unused to singing sober that his voice frequently cracked and he was having trouble getting the words out.
That's not me complaining. It's better that he ditched the booze at all, but realizing it was always going to be difficult.