New Googlebot IP? Or competitor spoofing user_agent?

This is wierd

[Friday]

My spider watching script sent me an email this morning that Googlebot visited with a new IP:
64.68.92.142

Arin.Net shows this for the new IP:
OrgName: Cable & Wireless

Which leads me to believe it's a competitor checking to see if I'm stupid enough to cloak by user_agent.
(I'm not!)

BUT, and here's the wierd part...
When I search for a legitmate Googlebot IP, like:
64.68.80.49
Arin.net returns:
Cable & Wireless SC3-1 (NET-64-68-64-0-1)
64.68.64.0 - 64.68.95.255
Google Inc. EC12-1-GOOGLE (NET-64-68-80-0-1)
64.68.80.0 - 64.68.87.255

SO....
Does Google buy bandwidth from Cable & Wireless?
Or what the heck is the deal?

I don't want to miss any Googlebot IPs, but I also don't want to add a bogus IP to my database that let's imposters seew what we're doing.

Ideas from people smarter than I am?

TIA
Friday

PS: While Googlebot (the real one) usually grabs my robots.txt file and then my homepage

this new spider grabbed my robots.txt file and then one other page, but not my homepage ("/").

[kovacs]

Yes afaik that is a googlebot ip.

[Friday]

kovacs,

How can you be sure?
An Arin lookup shows the IP address belonging to:
" Cable & Wireless "

And GoogleBot's block only goes from:
64.68.80.0 - 64.68.87.255

which does NOT incllude:
64.68.92.142

?
Help me out here.
How did you deduce this is a legitimate GoogleBot IP address?
I've been tracking these for years, and I've never seen this IP Address before.

Thank You VERY Much for Your Help,
Friday