Why is this simple macro not working?

I want to cast one spell if no modifier key is pressed, and a different spell if shift is pressed. I have this:

#showtooltip
/cast [nomod] Immolate
/cast [mod:shift] Conflagrate


I can cast without pressing shift, and immolate casts correctly. However, when I press shift, the icon changes so something is happening, but conflagrate doesn't cast.

I've tried changing it a bit like this:

#showtooltip
/cast [nomod] Immolate; [mod:shift] Conflagrate

In case that helped. I have changed 'conflagrate' to other spells but none of them cast.

I am using bartender, and have bound this key to the 'T key', but when I press shift-T, I don't get a conflagrate.

What could I have done wrong?

I worked it out. In keybinding, I had 'shift-T' mapped to 'pet attack'. So this was happening and overriding the macro.