All the solutions in three queries, very efficient, using LINQ:

static class Program
{
static IEnumerable<int> To(this int begin, int end)
{
while (begin <= end)
{
yield return begin;
begin++;
}
}

static int[][] permutations = { new int[]{ 0, 1, 2 },
new int[]{ 0, 2, 1 },
new int[]{ 1, 0, 2 },
new int[]{ 1, 2, 0 },
new int[]{ 2, 0, 1 },
new int[]{ 2, 1, 0 }};


static void Main(string[] args)
{
var trios = (from a in 1.To(9)
from b in 1.To(9)
from c in 1.To(9)
let value = a / (10.0 * b + c)
where value < 1
orderby value
select new { Key = new { a, b, c }, value }).ToList();

var ordSolutions = from a in 0.To(trios.Count - 1)
from b in 0.To(a)
from c in 0.To(b)
where trios[a].value + trios[b].value + trios[c].value == 1
select new[] { trios[a].Key, trios[b].Key, trios[c].Key };

var solutions2 =(from s in ordSolutions
from p in permutations
select new { A = s[p[0]], B = s[p[1]], C = s[p[2]] }).Distinct();

int count = 0;
foreach (var s in solutions2)
{
Console.WriteLine("{0}/{1}{2} + {3}/{4}{5} + {6}/{7}{8} = 1", s.A.a, s.A.b, s.A.c, s.B.a, s.B.b, s.B.c, s.C.a, s.C.b, s.C.c);
count++;
}
Console.WriteLine("Total: " + count);
Console.ReadLine();

}

}