SERVER #1 - Netware 5.1/SP8

SERVER #2 - Netware 6.5/SP4

SERVER #3 - Netware 6.5/SP4

Sometimes, when users login with SERVER #2 or #3 selected, they aren't
seeing SERVER #1. SLP seems to be working right, I think - DISPLAY SLP
SERVICES brings up the same list on all three servers and it brings it
up quickly.

Question 1: Does which server we select at login time make any
difference at all?

Question 2: Anything to check server side?

Question 3: Clients are all 4.90 SP2 - time to go to 4.91 and, if so, is
the latest full SP OK as-is?

Thanks in advance.