Pretty old topic but still no really good solution or workaround exists there on how to make DST working properly with the EWF enabled.
There has a bunch of suggestion been on how to make those two live together posted in the newsgroup: from using undocumented system's RealTimeIsUniversal flag to making your own time monitoring application that will switch or correct the system time if a DST time switch happens.
Perhaps, the only workaround that would work correctly is to disable the DST. Well, I can barely call this a workaround but at least with the DST off you won't have issues with the time changing unpredictably.
How to disable DST? Easy, just set this registry flag at run time:
On related note, you can mess around time zone settings offline in TD if you explorer the following key:
More info about this can be found on this XPe tip here.