error: Integration Server already defined when defining business system

While maintaining the Business System in the post installation, I gave the port number incorrectly for the pipeline URL. I tried to correct it by going to the business landscape and changed the port number to 8010 (the correct http port). After this, when selected the Integration Server in the drop down list for Business System Role, the text box for the Pipeline URL is not showing up anymore.

So, I deleted the business system, by selecting the remove button in the Business Landscape configuration page and tried to recreate it. Now I get an error that "Integration Server already defined". Could you anyone please help me with this problem?

Thanks you