Hi Suman
I'd find it unusual that it cannot be maintained in the Web UI for CRM 5.0.
Regardless of that.
I would record all Attributes assigned to the BP for that Attribute Set.
Clear all of the values assigned and delete the Attribute Set against that BP.
Then reapply the Attribute Set and the values you recorded.
I've seen similar issues to what you're experiencing and hopefully this will resolve it.
Regards
Arden