Can't change variables inside media queries

Hi

Having problems with $zen-column-count inside media queries, as they are in the default _responsive.scss : if I leave the variable inside the media query then it doesn't work, but immediately before it it does

So this, as it is in the starter kit:

@media all and (min-width: 960px) {

  $zen-column-count: 5;

  /**
   * The layout when there is only one sidebar, the left one.
   */
  .sidebar-first {
    /* Span 4 columns, starting in 2nd column from left. */
    #content {
      @include zen-grid-item(4, 2);
    }

....

- doesn't work, zen-grid-item uses the default value of $zen-column-count (which in this case is 1, so I get a 400% wide div)

but this

$zen-column-count: 5;

@media all and (min-width: 960px) {

  /**
   * The layout when there is only one sidebar, the left one.
   */
  .sidebar-first {
    /* Span 4 columns, starting in 2nd column from left. */
    #content {
      @include zen-grid-item(4, 2);
    }

....

... works as expected.

I've tried changing some other vars inside the media queries, and no effect there either, it just uses default value.

I'm thinking maybe it's something wrong with my SASS config, or something else on my server - anyone come across this?