How to use managem without lag?

[cnzjs 0]

Hi everyone:

as a mage,when you're casting,the worst thing is cast broken,so I thought macro can fix some,I made a macro like:

/cast Counterspell
/cast Frostbolt

and when you're casting Frostbolt,if your target start to cast something,you just keep clicking this macro so you will do Counterspell without any lag and keep casting Frostbold without any lag.

But,when I try to do this with managem,like:

/use "Mana Ruby"
/cast Frostbolt

The strange things happens:you just keep casting Frostbolt,and dont use ManaRuby(Unless you dont have enough mana to cast a frostbolt),but if you use this macro when you're moving,you do use ManaRuby,anyone can help me?

[Irisai 8]

I tried replicating this today and I didn't have any lag at all. Wish I could be of more help. :\