Issue Title Severity 1 Colour Using Value From Severity 0

For some reason, the text colour of a Severity 1 issue title is using the colour value from Severity 0, even though it's set properly in the severity cache.

Cache:

Array
(
    [skin4] => Array
        (
            [sev0] => Array
                (
                    [color] => #cccccc
                    [back] => transparent
                )

            [sev1] => Array
                (
                    [color] => #000000
                    [back] => #caecaf
                )

            [sev2] => Array
                (
                    [color] => #000000
                    [back] => #f0f3a4
                )

CSS:

.bug-severity-0,
.bug-severity-0 a:link, 
.bug-severity-0 a:visited, 
.bug-severity-0 a:active
{
	color: #cccccc;
	background: transparent;
}
.bug-severity-1,
.bug-severity-1 a:link, 
.bug-severity-1 a:visited, 
.bug-severity-1 a:active
{
	color: #cccccc;
	background: #caecaf;
}
.bug-severity-2,
.bug-severity-2 a:link, 
.bug-severity-2 a:visited, 
.bug-severity-2 a:active
{
	color: #000000;
	background: #f0f3a4;
}

Recaching causes the text colour of both severities to revert back to #000000.