ORA-03113 Import on NT (64Mb limit?)

Every time I try to import into my Oracle 8.04 database on NT I get a ORA-03113 near the end of the import. I've had no problem before when my import files were smaller but now that I've just nudged over 64Mb it fails. Coincidence? Or is there some system constraint that I'm hitting?

I can work around the problem by doing an export with rows=n and then a couple of imports into different schemas but it's all rather laborious and slow. Can anyone suggest a fix.

Many thanks,

• Bill.