Hi Yuichi,
First of all, were they not aware of the changes or functionalities of CRM 7.0 before upgrade? How and why did they make a call for upgrade then?
And what are the difference in behaviour that you have mentioned in 5.0 and 7.0 in SAP GUI?
There will be some changes & bug fixes we have to make from our end after upgrade. But beyond that, is there any functionality difference that you find in SAP GUI 7.0?
Are they using CIC?