We have had a case with slow logins on Win7/64bit clients on a couple
of sites. This could easily be seen;
1. installed win7 - login fast
2. installed nwclient - login fast
3. install zenagent - login slooooow......

Often, users saw the login successfull or something like that and then
had to wait for the next "welcome" before actually coming in to win7.

Strange solution,, at least for us...worth checking and see if someone
else can confirm the same...

After the above 3 steps, simply un-install nwclient, reboot,
install nwclient again...
and...that's it....,, login now fast again, fast as in before
zen-agent applied....

Note, we have NOT tested a setup from "scratch" were zen-agent goes in
first and then the nwclient and if that makes any difference.

Hopefully,, this can help someone else,,, again,, so far it's been the
same on each pc tested here...