I have a weird problem when specifying the ntp source interface. The command disappears after a relaod! The funny thing is that, when I specify the source interface with the ntp server togther "ntp server a.b.c.d source <interface>" the complete line is missing after a relaod.
I figured that problem out on a Cisco 876 with 12.4(24)T Advanced Enterprise.
If you have any ideas, pleas let me know.
It sounds like you are hitting this bug: