Hi,
I've noticed the same behavior when loading to terminal from a Console connection, which is probably understandable due to the buffer getting full.
It works fine from an SSH connection and when loading from a local file.
From SSH:
212.129.17.101; 212.129.19.140; 212.129.26.190; 212.129.26.221; load complete [edit policy-options prefix-list TEST] root@JUNOS# show | count Count: 346 lines
From File:
root@JUNOS# edit policy-options prefix-list TEST [edit policy-options prefix-list TEST] root@JUNOS# load merge /var/tmp/prefix2.txt relative load complete [edit policy-options prefix-list TEST] root@JUNOS# show | count Count: 346 lines
Cheers,
Ashvin