We hired this company over a year ago to develop a yahoo store. The owner is effectively holding my business hostage because he will not move content from his servers to the Yahoo Servers and is demanding that we approve their work before moving CSS and image files to Yahoo. I strongly recommend people not use Ydeveloper. They will not take our calls and have refused registered mailed attempts to contact them.
The biggest failures related to this company is their inability to properly communicate to the customer, and lack of quality assurance testing. Most everything they have added to our store has required checking and double checking to verify its work properly.