The reason it wont echo is because mIRC sees it as this:
Php Code:

alias bugtest { 
  if (1 == 1) { 
	if (2 == 1) { ;echo -a one | ;echo -a two }
	  else { echo -a False }
	}
  }

So the else is never evaluated as its become part of the if.
However the Remote's {} will see it differently

the "problem" is that while using IF ; doesnt make | lose its special meaning
Php Code:
alias bugtest { 
  if (1) { ;echo a hello | echo -a this triggers! }
  ;echo a hello | echo -a this doesn't trigger!
}

and it shouldnt really as well.
since it didnt encounter ; before if so it evals if and see an opening bracket. It sees that there are characters after { so it tries tokenizing | to get the commands it then finds out they are comments ";echo -a one" and ";echo -a two }" so therefor doesnt do anything and move to the next line which is else { echo -a False } it didnt find a conditionial before in the if statement clausal so else is ignored.

This is of course my own reasoning though smile

$maybe