Very Computer

I need to read past the logical end-of-tape in a SCSI DAT tape (Wantek).
After writing 32 files to /dev/nrmt, using "tar c" I rewound the tape
and wrote 1 more file to /dev/nrmt. Of course, I destroyed the first of the
32 files previously stored, but the most important problem is that when I try
to read after this new file, the tape supposedly finds a mark of end-of-tape
and refuses to read past it (I/O error, it says). I really need to access
the 1.4 Gb of data that I know exist after that mark.
So please tell me  how I can repair this terrible mistake, using ioctl calls
or low-level SCSI commands or maybe some recovery tool. Thank you very much.
                                        Juana Moreno