Connection timeouts
UTF-10 requires a bit longer to initialize. Thus, especially slower computers may not be done loading up completely and the server already registers the connection as "timed out" and terminates it. As a result, the player will end up in the cell again and will never connect.
To remedy that, you can have the players buy faster computers, or do the following on the server:
Advanced Options -> Network Settings -> TCP/IP driver -> Connection Timeout
should be set to at least 30 seconds (default is 15). This WILL cure this particular problem, as {hLk}Vash can confirm
Scoreboard problems
BEFORE even thinking about the scoreboard not showing all names or showing names doubly, answer yourself this question: are you using GOLD and just reconnected to the server or another server running the same map? In that case, disconnect, type "obj garbage", reconnect! Your problem is UGold related!
If that's not it, read the manual "players only" chapter and scroll down. Since no one ever reads manuals and just asks me again to answer all questions being answered in the manual, I will copy and paste the relevant section here:
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Console Command: utfdebug [arg]
Client debugging commands, they may work/not work and/or be be changed at will. [arg] may be:
prichain
This command argument will have your client log the currently replicated PlayerReplication chains. This debug command was introduced after getting reports about "missing players in the scoreboard". It has been determined with this command, that the chain as the server perceives it, is not always the same the server sends to the client.
priforcedupdate
If you have read the above text you are aware of the replication problem. Although some extra code has been introduced in the UTF 10 alpha 4 build to avoid the situation occuring, it may still happen. This command will enforce the server to resend replication data informing the client again about the current PlayerReplication chain.
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FROM NOW ON, WHEN YOU SEE NAMES ON THE SCOREBOARD BEING DROPPED, USE THE "prichain" COMMAND FIRST, THEN USE "priforcedupdate". NOW LOOK IF YOUR SCOREBOARD IS OK. EXIT UNREAL!
YOUR UNREAL.LOG FILE WILL CONTAIN 2 MEDIUM SIZED DEBUG BLOCKS TOWARDS THE END OF THE FILE. COPY AND PASTE THEN HERE ON THIS BOARD ALONG WITH YOUR MESSAGE IF YOUR SCOREBOARD ACTUALLY LOOKED OKAY AFTER THE 2ND COMMAND.
ANY MORE POSTS LIKE "NAMES DROPPED BLAH..." WILL BE IGNORED WITHOUT A LOGFILE SHOWING YOU USED BOTH DEBUG COMMANDS!