Raster layers on the Background Mapping in ProjectWise

Hi, I hope someone can help.

I am attempting to load an aerial raster mapping layer into the background mapping definition file in ProjectWise. I have created the connection and the graphical source and chosen the raster files (1000 ecw files of 500k-1mb locally cashed on the integration server where the geo web publisher modules are installed). 

When i come to add a layer in the map author and choose the source it says  “please wait while the server is processing the request”, then after a few minutes it says “Unable to access the Geo Web Publisher server”. Has anyone had any experience of this/know why i cant add the layer?

Thanks in advance,

Rob Farrell