SR 2254 is:
PROJCS["NAD_1983_StatePlane_Mississippi_East_FIPS_2301_Feet",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",984250.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-88.83333333333333],PARAMETER["Scale_Factor",0.99995],PARAMETER["Latitude_Of_Origin",29.5],UNIT["Foot_US",0.3048006096012192]]
The data i am using is defined as:
PROJCS["NAD_1983_StatePlane_Mississippi_East_FIPS_2301",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",984250.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-88.83333333333333],PARAMETER["Scale_Factor",0.99995],PARAMETER["Latitude_Of_Origin",29.5],UNIT["Foot_US",0.3048006096012192]]
However after looking at your response and testing the xy extents of my map i am thinking that the SR might be in conflict? i am using the default WKID:102100 esri basemaps as well at the moment in the flex viewer. Does the viewer automatically adjust for different systems ( i am guessing no) or do i need to convert my data to another SR?