I ran a whois (the linux command, more info than whois.com but the same service) on tendlife.com, the useful part of the output is below (there are no IPs in it, dont worry).
Code:
Domain Name: TENDLIFE.COM
Registrar: ENOM, INC.
Whois Server: whois.enom.com
Referral URL: http://www.enom.com
Name Server: NS1.DREAMHOST.COM
Name Server: NS2.DREAMHOST.COM
Name Server: NS3.DREAMHOST.COM
Status: clientTransferProhibited
Updated Date: 23-jan-2009
Creation Date: 05-nov-2006
Expiration Date: 05-nov-2009
Farther down the output, I see that they use WhoisGuard, as you said. Perhaps you could contact Dreamhost, which is, pretty apparently, from a traceroute on them and a whois on their actual IP address, their hosting provider. Try contacting them through one of the following (still output from a whois on their IP address, i'm in love with that command):
Code:
OrgAbuseHandle: DAT5-ARIN
OrgAbuseName:   DreamHost Abuse Team 
OrgAbusePhone:  +1-714-706-4182
OrgAbuseEmail:  [email protected]

OrgNOCHandle: ZD69-ARIN
OrgNOCName:   Network Operations 
OrgNOCPhone:  +1-714-706-4182
OrgNOCEmail:  [email protected]

OrgTechHandle: MNA53-ARIN
OrgTechName:   Nagel, Mark 
OrgTechPhone:  +1-714-706-4182
OrgTechEmail:  [email protected]