Why Does the Same Workflow Execute Differently on Different Accounts, Causing One to Run Out of Memory Unless the Setting is Raised to 512mb?

This does not offer a solution. As described previously, I took the same file and tested on two different account the memory usage was set to 256 on both. One runs out of memory and one processes the information without any issues. The only way I was able to correct this is to raise memory on the problematic account to 512. Remember, all parameters are identical otherwise.