please post your project
Can you have a look at the section "Multi-Byte Data Alignment" in the document:"AN84810 - PSoC® 3 and PSoC 5LP Advanced DMA Topics". I hope that this will answer your queries.(Link:http://www.cypress.com/documentation/application-notes/an84810-psoc-3-and-psoc-5lp-advanced-dma-topics).
Basically if the bytes are aligned, then the DMA transfer will be effective.