IE, CSS3 selectors, strange behaviour

If css rule has CSS3 selectors, which IE doesn’t understand, it passes them.

Doesn’t work:
tr:nth-child(even),
tr.even {
    background-color: #eee;
}

Work:
tr:nth-child(even) {
    background-color: #eee;
}

tr.even {
    background-color: #eee;
}