Edited Issue: CookieHeaderValue.TryParse() invalid date time format [298]

When I try to parse next cookie:

.ASPXAUTH=4739F5D3BE64150EBD2259869A846B3BC2F30A09B3666868FFBC5A11435BA1998D7FF3C2AF5E8ACB9E88FCF2C087B0959C53C590583799831582F3AE42F41349FA1589383FF41B2C445E100F56AEE464033F74A992DA4ED11AB99976E1F44E86AAD4571E952AEA3519926F4C58AC1D8748A5C872ECA0A7872E7E2E136F4999EFDC97698C30A2ECD1FD249F2B37EC3A8AE49EDC47DCA7E9C23C84F0D469E0495F51A25485F73CF07405147741D6AC3620; expires=Tue, 31-Jul-2012 20:18:50 GMT; path=/; HttpOnly

using CookieHeaderValue.TryParse, I always get FALSE result. It seems to me, that there is no proper date format acceptable with cookie expire date in System.Net.Http.Formatting/FormattingUtilities.cs