This error does not exist on p0.
I get the dreaded ASCII-8BIT not compatible with USASCII error in _write_sst in
class Spreadsheet::Excel::Writer::Workbook.

I tried to monkeypatch it by forcing the encoding utf8 on data, header and packed
but while this worked on my development machine, the server then produced an empty spreadsheet.

spreadsheet (0.6.5.1) lib/spreadsheet/excel/writer/workbook.rb:515:in `block in _write_sst'
spreadsheet (0.6.5.1) lib/spreadsheet/excel/writer/workbook.rb:502:in `each'
spreadsheet (0.6.5.1) lib/spreadsheet/excel/writer/workbook.rb:502:in `each_with_index'
spreadsheet (0.6.5.1) lib/spreadsheet/excel/writer/workbook.rb:502:in `_write_sst'
spreadsheet (0.6.5.1) lib/spreadsheet/excel/writer/workbook.rb:489:in `write_sst'
spreadsheet (0.6.5.1) lib/spreadsheet/excel/writer/workbook.rb:439:in `write_from_scratch'
spreadsheet (0.6.5.1) lib/spreadsheet/excel/writer/workbook.rb:620:in `write_workbook'
spreadsheet (0.6.5.1) lib/spreadsheet/writer.rb:18:in `block in write'
spreadsheet (0.6.5.1) lib/spreadsheet/writer.rb:17:in `open'
spreadsheet (0.6.5.1) lib/spreadsheet/writer.rb:17:in `write'
spreadsheet (0.6.5.1) lib/spreadsheet/workbook.rb:109:in `write'

Date: 2011-08-04 11:46
Sender: Zeno R.R. Davatz

Please report any further issues to:

http://groups.google.com/group/rubyspreadsheet

with your sample file and sample code posted on github and linked
to above mailing list.

Seems to be another inconsistency in Ruby that we have to fix
in Spreadsheet.

Best
Zeno

Date: 2011-02-16 07:31
Sender: Zeno R.R. Davatz

See the Mails here from Paul Howson: 

http://url.ba/abcc