Yes, I reflashed with format option. and the log config. it says: 'Back to clean Irex default etc". I didn't think to request the SDK again, but I did and it downloaded OK.
I'm happy to say my iLiad now reads mobi and txt again, but I can't read epub as yet, because the FBreader and NewLister won't install (gives a tiny green flicker and that's it). Thank you very much for helping me.