Whilst I am not really familiar with this format all that much, I would say there is at least one difference between the first entry and the rest.
Your first map entry is:
map /SeaToolsDOS222ALL576.ISO (hd32)
Here you have capitalised the extension 'ISO' from the previous line and have included (hd32) at the end.
None of the other first map entries have these things. Hope that helps.