[nsp] missing "controller t1" lines after upgrade to 12.0(27)S1

[Ed Ravin]

We upgraded a 7513 with RSP4, one CT3, and a few FastE interfaces
and T3 interfaces to 12.0(27S1 from 12.0(25)S1.  Router is running BGP
with a full view of the Internet, Netflow, a bunch of ACLS and GRE tunnels.

We immediately noticed two major problems:

(1) the router began running out of memory, big time.  The Turbo ACL
process kept crashing.  When we did "no access-list compiled" to free
up some memory, the "Virtual Exec" task began crashing.  We could not
change the config remotely (writing to "startup-config" gave back a
"file in use" error), and we couldn't even view the running config
(the prompt came back immediately without printing anything).
We did a few tweaks to our BGP setup to reduce memory usage, and
things are stable now (i.e the config commands work as expected, except
for (2) below).

(2) the router no longer displays its entire config for the CT3.  It
will boot properly and the T1 channels come up, but if you do a "show
running-config" these lines are missing:

>  t1 1 timeslots 1-24
>  t1 2 timeslots 1-24
>  t1 3 timeslots 1-24

Etc., all the way down the line for all our active channel.  We can
type in the commands again in config mode, and even bring up a new
interface, but these lines don't show when we do "show running".  If
we save this config and reload, then the T1 interfaces don't come
up because the timeslot statements are missing.

We haven't tried rebooting since we fixed the memory issue (I'm waiting
for another maintenance window to rear its ugly head), so I suppose
it's possible it'll behave better at the next reload.  But can anyone
offer opinions on these questions:

(1) why does the newer IOS in the same stream suddenly have memory problems?
Looking at my Cricket graphs, it looks like we were approaching memory
constraints before the upgrade, but I wouldn't expect such catastrophic
differences in the new version.

(2) why do the "t1 NNN timeslots 1-24" statements disappear like that?
As far as we can tell, no other config statements are missing, just a
few rearrangements like the "boot-marker" statements and the "no ip cache
flow" statements moved from the subinterfaces.

	-- Ed