Intelligent SS/Dev spam macro

Has anyone had any luck with useing cast sequences with a condition? I've recently been switching between Heroics and normal instances a lot and duel wield whenever I'm in a normal instance. Since I'm lazy and enjoy banging my head against the wall I've been spending hours trying to build and test a macro while raising my 2 hander skills rather then just continueing to switch the buttons on my bars.

Basically the macro checks if I have a shield. If it does then it goes into my old SS/Dev sequence which resets after 6 seconds since I rarely get 3 Devastates in before the cooldown is up. If I don't have a shield equipped I just want it to spam Devastates.

I've tried variations of:
/castsequence reset=6 [equipped:Shields] Shield Slam, Devastate, Devastate, Devastate; [noequipped:Shields] Devastate, Devastate, Devastate, Devastate
/startattack

/castsequence [equipped:Shields] Shield Slam, Devastate, Devastate, Devastate
/stopcast
/castsequence [noequipped:Shields] Devastate, Devastate, Devastate, Devastate
/startattack

This one actually worked right up until I put in the reset=6. The above also worked with just Devastate in the second line as a /cast again right up until I added the reset.

I know I could just do it the old fasioned way, the same way I've been doing it for ages, but I like a challenge. Has anyone run into this type of problem before or able to spot an error?

There's absolutely no reason to use /castsequence for the second one. For all practical purposes, a /cast line is the same.

What messages do you get when you try it as this? Nothing else.

/castsequence reset=6 [equipped:shields] Shield Slam, Devastate, Devastate, Devastate

Unfortunately I can't go in-game and check it at the moment (I'm taking a hiatus from my main's server).

Please consider me an idiot. This is what I get after building 80 blades from the ground up in a single day. Norrath your macro works fine. It's actually one that I had tried and dismissed. I wasn't watching the combat log, I was looking at the icon all night and it never changed from the ? like it should be.

Hmm.. course that still gives me a challenge. Cast sequences don't break the ?, modifiers and conditions don't.. not even the shield equipped with a modifier... (I've a single key that handles Shield Bash/Pummel based on shields and stances as is posted in Mozman's thread with an additional CRTL modifier to use Concussive Blow).