long delay between circuits..

Hello,

I want to hear advices from gurus,

  Our network use transit service from UU.NET in PaloAlto IX.
  
  ## the result of traceroute from our network to www.sun.com
  traceroute to Sun.COM (192.9.49.33), 30 hops max, 40 byte packets
   --<snip>--
  4 INET-PA-GW.nuri.net (203.235.119.253) 147 ms 145 ms 143 ms
  5 911.Hssi5-0.GW1.PAO1.ALTER.NET (157.130.192.145) 170 ms 169 ms
173 ms <-----@@@@
  6 119.ATM3-0.XR1.SCL1.ALTER.NET (146.188.144.78) 486 ms 434 ms 441
ms <-----@@@@
  7 146.188.145.157 (146.188.145.157) 432 ms 440 ms 443 ms
  8 core7-hssi5-0.SanFrancisco.mci.net (206.157.77.73) 408 ms 457 ms
425 ms
   --<snip>--

  (INET-PA-GW.nuri.net is our ROUTER.)
  Between hop 5 and hop 6, it took about 300 ms.

  It seems the problem of UU.NET as simple analysis..
  If the circuit has a problem, the all connections between PAIX and
uu.net have
  problems also.

  Has anybody the same problem ?

Thanks in advacne..

Sincerely,

PS) Was the location of the www.sun.com moved to east coast?
     I remember that www.sun.com was directly connected with UU.NET, but
     today the traceroute shows it is connected via MCI and the location
is Boston.
     Is it right ? or the result from routing unstablilty ?