Engine RwEng-0 Crashed when using spreadsheet output with national chars

 Hello, I'm using oracle reports 10.
I'm getting an error, when running a report with SPREADSHEET output
It works fine, when I'm using PDF or HTMLCSS.

It's not a big report (Just 3 pages, when using PDF). But has one field which contains text data up to 2000 unicode characters.

I think there is a problem with spreadsheet output and that long text field with unicode (national) characters.
Because I've tryed to replace every national character (2 bytes) in the text with something like 'AA' (also 2 bytes) - spreadsheet output worked fine.
Also spreadsheet output works fine when text field contains about 400 characters (including national characters)