I recently had a Lapsang Souchong strength problem. My problem is probably completely different than yours. I mentioned it in a TeaDay post, but thought I'd mention it here also. It might be of help to someone who finds this thread searching for tea strength problems.
I tried a couple of Lapsang Souchong samples from Upton Tea. I liked them, and ordered a tin of one of them. That's one of the things I like about Upton. Most of their teas can still be ordered in tins. Anyway, when the tea arrived I took the tin to work. With my first steeping attempt at work the tea was weak, and the liquor was much lighter than the sample I had tried at home. I tried another mug with more leaves than the first. It was better, but still not right. I took the tin home over the weekend. I tried some at home and it came out great. Back at work Monday I tried the tea again with the same weak tea results as the first attempts. After some head scratching the problem finally dawned on me. At home I was steeping in an Adagio personaliTEA pot. At work I was using an Adagio glass mug/infuser. The mug's infuser is made of a thin sheet of stainless steel with very very tiny holes in it. The personaliTEA's infuser is made of a wire mesh. One reviewer described the tea's liquor as "thick", much like coffee. The mug's infuser was too fine for the tea in question. I tried another steeping keeping all of the equipment used the same, except leaving out the infuser. I then strained into another mug with a wire mesh tea strainer. The tea came out great, dark and rich. I think it might actually be a little better than the results I got with the personaliTEA pot. I was already questioning whether infusers were a good or bad thing. Before long I might completely kick the infuser habit.