WinSCP version 4.3.2
Client OS: Win XP
Server OS: Linux (Ubuntu 8.04 LTS)
Both client and server correctly switched to DST. Client and server clocks are sync'd to within a second. Here's an example with file created on the server:
jimrick@ubuntu2:~/ftest$ nano test
Mon Mar 14 15:29:01 CDT 2011
jimrick@ubuntu2:~/ftest$ ls -l
-rw-r--r-- 1 jimrick www-data 16 2011-03-14 15:28 test
WinSCP shows the file test timestamp as 4:28:50 PM or 1 hour ahead of the actual time created. It also uses the same (incorrect) timestamp when copying the file to the client.
There seems to be a problem in how WinSCP handles DST.