A0 is so called non-breaking space. While it may (should) be possible to make SAP Spool system to recognize and process them as "normal" spaces (on our SAP_BASIS 740 SP 12 system the preview is correct, for example), if the there is no real reason for having them, instead of trying to fix the output, I'd try to find out where are they coming from fix them at source - migrate the descriptions for example. CL_ABAP_CONV_IN_CE=>uccp( '00A0' ) call returns non-breaking space as character.
cheers
Jānis