Joanne,
You will have MAJOR issues. BI 4.1 has many NEW features NOT in BI 4.0 w/ SP3, for this reason your content will NOT work. If you update your BI 4.0 to BI 4.0 w/ SP8 or better then you would have a better support option but still NOT 100% supported.
The problem is that many NEW features have been released since BI 4.0 w/ SP3, you current BI 4.0 is too old. The biggest changes / enchancements are with WebI.
Regards,
Ajay