new [] and length

[Carlos Santander]

Are there any differences between these two fragments, besides the syntax?

char [] buf = new char [count];

char [] buf;
buf.length = count;

I ask because when I use the first method and then pass it to Mango's 
Atoi.parse, sometimes I get:

Error: ArrayBoundsError 
/Users/carlos/Development/d/mango-2.0/mango/convert/Atoi.d(175)

But when I use the second method, I never get that error. In both cases I'm 
using the same data, which unfortunately is too large and complex to make a 
reduced test case.

I'm using GDC 0.17 on Mac. Could this be Mac only or GDC only?

-- 
Carlos Santander Bernal