Hi Ricardo,
Many thanks for your reply, I have gone through the notes which you have provided , But we have maintained data properly (i.e.with correct master data),There are two systems involved for the product category (i.e. srm,ecc) ,as a result system is not able to pick a unique category,Then from the notes it is understood that there is no soution for this type of error(except to select category from Search help F4).
Thanks,
Sai