[Proj] Map Re-projections

[Ryan Ollerenshaw]

When using proj4 with MapServer i am having a problem reprojecting some of my
raster datasets.

Some of the datasets have a prime meridian at 0 degress and others that have a
prime meridian at 90 degrees and i need these raster datasets to line up. but
when i specify a map projection as:

PROJECTION
  "proj=cc"
  "lon_0=90w"
  "ellps=WGS84"
  "datum=WGS84"
END

and a layer projection as:

PROJECTION
  "proj=cc"
  "lon_0=0"
  "ellps=WGS84"
  "datum=WGS84"
END

Rather then the layer geting reprojected to the map projection I get a blank
image.  I do however get a different map image of i just change the projection
name of the map file to some like: lcc or merc.  But why am i getting a blank
image when i try to shift the prime meridian?

Thank you for any help you can provide,
-Ryan