Took me awhile to get what should have been a simple Linux P2V done at work!
This stuff wasn't clearly stated anywhere--I couldn't find anyone with similar issues, so I'm posting this up hoping to help someone else out in the future. Working with VMware they pointed out the lack of support for dvSwitches after passing through a few levels of support their.
Error: Unable to connect to the Converter helper server on the target virtual machine
Cause: VMware does not support the usage of dvSwitches for Linux Conversions! Make sure the network you select isn't a dvSwitch
Error: Unable to obtain the IP address of the target virtual machine running the Converter helper server.
Cause: Related to the above error, relying on DHCP while using a network that is a dvSwitch for a conversion will get you the above error.
The last task before removal will be something like: Connecting the Converter helper ISO image to the target virtual machine.
Cause: ESX(i) 4.1 is not supported at this time by VMware Converter--this was with version 4.0.1--the latest version at the time this post was made.
Leave a comment if these notes helped you out or if you have any other uncommon errors you ran into.