DST changes are still hard-coded for the 1st Sunday of April and the last Sunday of October in many operating systems, applications, computers and network devices including firewalls, routers, switches, NTP appliances, time clocks, PBX systems, IVR/ACD systems, cell phones, PDAs, photo copiers, fax machines, and all the other devices on your network that recognize or require time/date to operate properly.
To accommodate the DST change, most of those systems will likely need either patches or manual fixes. The fastest way to find vendor patches is to query one of the popular search engines for ' vendorname or domainname daylight saving time 2007'.