Resolution:
This happens when wrong server port is specified to be "61072" in the Designer --> Workflow Server Connection.

Command line statement to excute icjava server:
$java -Djava.security.policy=&lttibcohome>/tra/5.1/icjava/6.2/java.policy" &lticjavaserver name> -p &ltport> -d &lttibcohome>/tra/5.1/icjava/6.2  -h &lthostname>

When you want to connect to the WF Server using the Proxy Server. In the Designer : "Workflow Connection" --> "Advanced" --> select "Connect using Proxy Server"
The parameters here are refered as given in the command used above to start IcJava Server.
Proxy Server Name: &lticjavaserver name>
Proxy Server Host: &lthostname>
Proxy Server Port: &ltport>

By default the port number in the above acitivity in the designer will be "61071", you will need to change this value to whatever port#  you have specified earlier in the command line to start the IcJava Server.

If port number "61072" is entered instead of the port # given in command line and then you try to connect to the IcJava Server  following error is reported.

ContentServer: Cannot create request java.util.NoSuchElementException
java.util.NoSuchElementException
        at java.util.StringTokenizer.nextToken(StringTokenizer.java:259)
        at com.inconcert.servlet.engine.IcHttpServletRequest.parseHeader(IcHttpServletRequest.java:79)
        at com.inconcert.servlet.engine.IcHttpServletRequest.&ltinit>(IcHttpServletRequest.java:132)
        at com.inconcert.servlet.engine.IcServletEngine.run(IcServletEngine.java:204)
        at IcJavaServer.main(IcJavaServer.java:269)
null

IcJavaServer reports an error when trying to connect from with in the designer using proxy server connection - "ContentServer: Cannot create request java.util.NoSuchElementException".