I'm not sure if it'll help, but let me try: I faced such a problem during import of a large table into a clear database (after its re-creation). It had several extents and, due to large pctincrease parameter (like yours) next extent was too large.
What did I do? Luckily, I was able to create a table using CREATE TABLE statement as I had a source file (fixed storage parameters first) and then imported data into it (using IGNORE=Y).
P.S. I don't recognize the code "US37" ... where does it come from?
your table needs an extent of 500MB must fit into a single chunk within that tablespace ..
oracle no longer recommends the use of pctincrease as of 7 something...
because extents of odd sizes fagment your tablespace to many chunks that can't used any more because many next extents don't fit into this chunks.
you can pipe to sql stmts of your exp.dmp file to a textfile and then edit the pctincrease and next and even the extents you are going the allocate first ...