Is pCL-Eco suitable for packaging viruses that used to infect human cells? - (Jul/19/2011 )

we cotransfected 293T cells with pCL-Eco and pBABE-puro, collected supernatants to infect human 5637 bladder cancer cells.
But failed.
Addgene said about pBABE: "Weinberg Lab recommends using pUMVC (Addgene #8449) and VSV-G (#8454) for packaging. The pCL-Eco plasmid listed in their protocol should be substituted with pUMVC." http://www.addgene.org/1764/
Is it right? why?

Is pCL-Eco suitable for packaging viruses that used to infect human cells?

pCL-Eco is only suitable for Rat and Mouse cells..........you need pCL-Ampho or VSV-G for generation of retrovirus capable of infecting human cells