CRM ICAGENT: Data cannot be maintained for set type COM_COMMERCIAL?

Hi Team,

I am getting issue in ICAGENT role.problem is icagent ,i base objects screen user enters serial number then automatically remaining fields are get filled and if we open any partner details on result list its get opened ,all fields are filled ,but only one field purchase price is not get filled .

For this i have edited on the screen if i select manually purchase date after enter i am getting error Data cannot be maintained for set type COM_COMMERCIAL.

So how to resolve this issue ..could you please provide my solutions for this.

Thanks

Kalpana