Modifications made in Settings.LiveUpdate are saved, but on the first launch of LiveUpdate are back to default.
You need to change time-out value for LiveUpdate due to LU 1835 error. You change the PREFERENCES\INTERNET_CONNECT_TIMEOUT and PREFERENCES\INTERNET_READ_DATA_TIMEOUT values from 45 to 600 seconds (in Settings.LiveUpdate). Then you launch LiveUpdate but you still receive LU 1835 error. You control Settings.LiveUpdate and you see that time-out values are back to the default 45 seconds.
Probably LiveUpdate is corrupted
Reinstall LiveUpdate and change again time-out value to 600 seconds.
Symantec Endpoint Protection Manager RU5 and LiveUpdate 3.3 installed on Windows Server 2003 Standard sp2