Hi,
Thanks for your feedback on this issue. This was a known shortcoming (see link to the bug report below) in the ComboBoxAdv that has been taken care of in our v3.2 releases.
Defect #32 - Problem matching non-alphabetic entries in DropDownListMode
Please upgrade to v3.2.1.0 by logging into your Direct-Trac account and let me know if you need further assistance.
Regards,
Guru Patwal
Syncfusion, Inc.