[nsp] Trouble after upgrade

[aaronh at amerion.net]

Hi everybody, first time posting here, so please be kind  ;)

Last night I upgraded IOS on one of our 7513 routers, and ever since,
traffic graphs seem to be ..odd.  We're using cricket, which we've been very
happy with to this point.  Anyway, since the upgrade, at the beginning of
each hour traffic appears to stop on each serial interface on the router. 
I've verified that traffic doesn't actually stop, there are still packets on
the wire, but the graph dies for a few minutes.  Has anyone else experienced
this kind of thing?  It's only happening on serial interfaces, ethernet
appears to work fine.  I know this is somewhat offtopic, so I'll ask a
question that isn't to cover my bases.  This is the other oddness:

phnx1-7513-nap#sh int Serial8/1/0/21:0
Serial8/1/0/21:0 is up, line protocol is up
  Hardware is cyBus CT3
  Internet address is 206.124.161.73/30
  MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec,
     reliability 255/255, txload 1/255, rxload 126/255
  Encapsulation HDLC, crc 16, loopback not set
  Keepalive set (10 sec)
  Last input 00:00:02, output 00:00:02, output hang never
  Last clearing of "show interface" counters 01:26:22
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: weighted fair
  Output queue: 0/1000/64/0 (size/max total/threshold/drops)
     Conversations  0/2/256 (active/max active/max total)
     Reserved Conversations 0/0 (allocated/max allocated)
     Available Bandwidth 1152 kilobits/sec
  5 minute input rate 16923000 bits/sec, 2180 packets/sec
  5 minute output rate 9000 bits/sec, 171880 packets/sec
     696444 packets input, 662199442 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     55426268 packets output, 567946 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 output buffer failures, 0 output buffers swapped out
     0 carrier transitions no alarm present

Notcie that the 5 minute input rate is over 2mb/s, and that while the 5
minute output is only 9kbits/s, it seems to be pushing 170,000+ packets/sec.
 Neither of these seems right to me, and I've verified that the interface is
NOT pushing 170,000 packets/sec.  I'm wandering around google and cisco.com
right now, but have found nothing of use so far, so thought I would ask here
and see if anyone has run into this particular brand of strangeness before.
 I appreciate any advice anyone has to offer.  Oh, and we're running
12.2(13)T5 (we'll be moving to 12.3 as soon as I can talk the boss into
spending the money on flash).  If I haven't provided enough info, let me
know, I'll be happy to help you help me  =)

Thanks,
Aaron Howell
--
Network/System Administrator
Amerion, LLC