There is an issue with the PetaPoco Paging regex. This usually becomes an issue on long SQLs but others can be affected.
This can be fixed by replacing the rxOrderBy Regex with
public static Regex rxOrderBy = new Regex(@"\bORDER\s+BY\s+(?:\((?>\((?<depth>)|\)(?<-depth>)|.?)*(?(depth)(?!))\)|[\w\(\)\.\[\]""])+(?:\s+(?:ASC|DESC))?(?:\s*,\s*(?:((?>((?<depth>)|)(?<-depth>)|.?)*(?(depth)(?!)))|[\w()\.[]""])+(?:\s+(?:ASC|DESC))?)*", RegexOptions.IgnoreCase | RegexOptions.Multiline | RegexOptions.Singleline | RegexOptions.Compiled);
or by using NPoco, a much enhanced fork of PetaPoco with API compatibility.