Crystal reports with database character set change to unicode

[RogersJ]

Old environment:
Oracle 9.2.0.5
Database character set US7ASCII
Crystal Reports 7 & 8.5

New environment:
Oracle 10.2.0.2
Database character set UTF8 (nls_length_semantics = char)
Crystal Reports 7 & 8.5

I'm in the process of upgrading database versions from 9.2.0.5 to 10.2.0.2. Along with the version change the we also changed from single byte character set to multibyte character set.

My customer whilst testing in the new environment encounters the error:
'Blob field or memo field can not be used in a formula'

In the Oracle 9 database the field is defined as
poitemtext VARCHAR2(255)

In the Oracle 10 database the field is defined as
poitemtext VARCHAR2(255 char )

Does any one have any suggestions for my customer that may help them?

Thanks, Jan

Note: I'm the DBA not the Crystal Reports person, so if the details are fuzzy I apologize in advance. I can chase them up from the customer should you need them.