OS is centOS 5.5 x64, rpm's are as follows:

• tomcat5-jsp-2.0-api-5.5.23-0jpp.9.el5_5
• tomcat5-common-lib-5.5.23-0jpp.9.el5_5
• tomcat5-servlet-2.4-api-5.5.23-0jpp.9.el5_5
• tomcat5-server-lib-5.5.23-0jpp.9.el5_5
• tomcat5-5.5.23-0jpp.9.el5_5
• tomcat5-jasper-5.5.23-0jpp.9.el5_5

telnet localhost 8080
Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
GET / HTTP/1.0
Host: localhost

HTTP/1.1 400 Bad Request
Server: Apache-Coyote/1.1
Date: Thu, 16 Sep 2010 15:06:21 GMT
Connection: close

alternatives --display java output:

alternatives --display java
java - status is manual.
 link currently points to /usr/lib/jvm/jre1.6.0_21/bin/java
/usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/java - priority 16000
 slave keytool: /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/keytool
 slave orbd: /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/orbd
 slave pack200: /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/pack200
 slave rmid: /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/rmid
 slave rmiregistry: /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/rmiregistry
 slave servertool: /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/servertool
 slave tnameserv: /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/tnameserv
 slave unpack200: /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/unpack200
 slave jre_exports: /usr/lib/jvm-exports/jre-1.6.0-openjdk.x86_64
 slave jre: /usr/lib/jvm/jre-1.6.0-openjdk.x86_64
 slave java.1.gz: /usr/share/man/man1/java-java-1.6.0-openjdk.1.gz
 slave keytool.1.gz: /usr/share/man/man1/keytool-java-1.6.0-openjdk.1.gz
 slave orbd.1.gz: /usr/share/man/man1/orbd-java-1.6.0-openjdk.1.gz
 slave pack200.1.gz: /usr/share/man/man1/pack200-java-1.6.0-openjdk.1.gz
 slave rmid.1.gz: /usr/share/man/man1/rmid-java-1.6.0-openjdk.1.gz
 slave rmiregistry.1.gz: /usr/share/man/man1/rmiregistry-java-1.6.0-openjdk.1.gz
 slave servertool.1.gz: /usr/share/man/man1/servertool-java-1.6.0-openjdk.1.gz
 slave tnameserv.1.gz: /usr/share/man/man1/tnameserv-java-1.6.0-openjdk.1.gz
 slave unpack200.1.gz: /usr/share/man/man1/unpack200-java-1.6.0-openjdk.1.gz
/usr/lib/jvm/jre-1.4.2-gcj/bin/java - priority 1420
 slave keytool: /usr/lib/jvm/jre-1.4.2-gcj/bin/keytool
 slave orbd: (null)
 slave pack200: (null)
 slave rmid: (null)
 slave rmiregistry: /usr/lib/jvm/jre-1.4.2-gcj/bin/rmiregistry
 slave servertool: (null)
 slave tnameserv: (null)
 slave unpack200: (null)
 slave jre_exports: /usr/lib/jvm-exports/jre-1.4.2-gcj
 slave jre: /usr/lib/jvm/jre-1.4.2-gcj
 slave java.1.gz: (null)
 slave keytool.1.gz: (null)
 slave orbd.1.gz: (null)
 slave pack200.1.gz: (null)
 slave rmid.1.gz: (null)
 slave rmiregistry.1.gz: (null)
 slave servertool.1.gz: (null)
 slave tnameserv.1.gz: (null)
 slave unpack200.1.gz: (null)
/usr/lib/jvm/jre1.6.0_21/bin/java - priority 2
 slave keytool: (null)
 slave orbd: (null)
 slave pack200: (null)
 slave rmid: (null)
 slave rmiregistry: (null)
 slave servertool: (null)
 slave tnameserv: (null)
 slave unpack200: (null)
 slave jre_exports: (null)
 slave jre: (null)
 slave java.1.gz: (null)
 slave keytool.1.gz: (null)
 slave orbd.1.gz: (null)
 slave pack200.1.gz: (null)
 slave rmid.1.gz: (null)
 slave rmiregistry.1.gz: (null)
 slave servertool.1.gz: (null)
 slave tnameserv.1.gz: (null)
 slave unpack200.1.gz: (null)
Current `best' version is /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/java.

Same occurs trying HTTP/1.1, and I am at a complete loss as to why.