set order reset to the last attribute

[henkvalk]

First, thanks for your great module, working very nice.

When I filter with multiple attributes, and after filtering I change the sort order, the filter results resets to the last attribute.

For example:

Brand : Nike, Adidas
Color : black, white, red

I choose Nike and red, so the URL is /nike-red. When I change the sort order to asc, the URL is changing to /red?dir=asc&order=position instead of /nike-red?dir=asc&order=position

When I first choose 'red', secondly 'Nike', my url is /red-nike, when I chang the sort order to asc, the URL is changing also to /red?dir=asc&order=position

Also with changing grid to list, and others from optionbar.