Cisco 677 delete nat entry multiple ports

[lovalles]

entry
10.0.0.206 6660-6669 64.32.88.77:6660-6669


when i try to delete this nat entry with multiple ports using the command and follow:

cbos#set nat entry delete outside 64.32.88.77
1 out of 297 NAT entries have been remove

then i use the write and reboot command
but when i reconnect to the router i see againg the nat entry i just deleted. This only happends to me with the port range entries i have made.

I also try to using the set nat entry delete all
then the write and reboor command.
but againg all the range ports entries still there.
anyone?