Can a player that uses Dual Strike benefit from Blademaster?

I see no reason why he should not.

Blademaster lets you re-roll missed attacks with bladed weapons. Dual Strike lets you combine to weapons into one attack. I see no conflicts here.

The description of Blademaster reads that it can be used "When attacking with a sword or a knife of any type…"

Dual Strike is a single attack made with two weapons so I think that it is not very clear if Blademaster applies.

Exeviolthor said:

Well are you using swords with these attacks? are you combining a sword and mace? What are you actually asking?

Dual strike and Blademaster work together when you use any combination of swords, knifes, chainswords, and power swords with one another as long they are part of the list that Blademaster says you can use. If you use any of those weapons listed with another melee weapon that is not on the list I would say that Blademaster would not work at all.

Could you explain why this doesn't seem clear to why Blademaster and Dual Strike would not make sense working together?

First of all let me clarify that I agree with you that it makes perfect sense for them to work together and that is the way we play it in our group.

It is just that we were not sure that what we do is correct because based on the description of Blademaster one could say that it applies only when you use one weapon to attack. For example it would be more clear if it read "When attacking with swords or knifes of any type…". When it reads "…a sword…" it can be interpreted as "…one sword…".