DNS Server Issue

I have two DNS Servers Windows 2003
They are external facing, resolve domains (URLs) for the public.
When I use A Records everything works fine, except if I manually Reload From Master
But when I use CNames records the secondary dns zone (on the second server) will not reload automatically
If I right click on the zone and choose reload it loads the zone until it expires.

If I choose Reload From Master it will fail and locks the zone.

I manage 800 domains and it is easier admin if I can use cnames.

If anyone can help thanks.