We have a server "Windows 2008 R2 x64"/"Windows 7 x64" with an instants client and when we want to connect to database version 10.1.0.5 that,
It's running in a server "Windows 2003 sp2", the connection is very slow, about 26 seconds but if we connect to this database from a server
"Windows XP sp3"/"Windows 2003 sp2" the connection is much faster, it's immediate.
The instants client of both servers are the same, they were installed several versions, like: 10.2.0.1, 10.2.0.5, 126.96.36.199, 188.8.131.52 and the results
were the same.