GOT IT !

If I run  following query, it's all fine ...

select ccc_id, town, '*' + rtrim(TOWN) + '*',

'*' + replace(rtrim(town), char(0), '') + '*'

from CLI_CONTACT_CHANGES

where FK_CLIENT_CONTACLC_ID = '244_CORRESP'

Thanks a lot Luis for your help!!! Problem quiclkly solved 🙂