VAT Code is Missing or Out Of Date [Message 173-108]

Hi Friends,

We run SAP B1 2005 PL 50, while trying to add an AP invoice using a defined tax code, however I get this error message"VAT Code is Missing or Out Of Date [Message 173-108]".

I have gone to Tax codes set-up(Administration->setup->financials->Tax->Tax Code) to check the tax code in question,it has not column where it's validity is specified, it only has an "Effective from" date.

Do you know of any possible work arounds?

Thanks in anticipation of your help.

Regards