Galaxy Clusters have wrong size in different projections

[gr22]

I added a Galaxy Cluster in the Catalog file ngc_merged.txt like this:
0 0 0 12.528880555556 11.790166666667 8.630000000000 350.000000000000 275.000000000000 105.000000000000 GxC Virgo cluster

Now if I do a stereographic projection the cluster is shown bigger (m98 for example is inside)
With alt_az projection the cluster is smaller (the same galaxy is outside the boundaries)

Here is a sample file:
(change between the projections to see the difference)

angular_width=35
coords=ra_dec
projection=stereographic
ra_central=12.508880555556
dec_central=12.490166666667
output_filename=/tmp/GalaxyCluster.pdf
width=21