Oracle Database Discussions

Hello -

1. We have one database (db1) in characterset US7ASCII and does store some special characters like microsoft word's curly quotes etc.(eg “abc”) and renders and displays them correctly from Web application in the browser.
2. We have another database(db2) in characterset WE8ISO8859P1 character set behaves the same as above.

But the issues faced are as follows -

1. When we try to export the data from db1 (US7ASCII) and imported in db2 (WE8ISO8859P1). It could not convert microsoft word's curly quotes etc.. could not convert correctly and replacing those with upside-down questionmarks.We tried different NLS_LANG options while export/import. But nothing seems to be working.

Question - Not able to understand why the problem for the data conversion when both characterset databases work fine with those special characters, stores them fine.Besides WE8ISO8859P1 is strict superset of US7ASCII.

2. We decided to alter database character set of db1 (US7ASCII) to WE8ISO8859P1 , as we need to store french characters in the future.
WE8ISO8859P1 is strict superset of US7ASCII and both are single bytes, storage 8 bits for 8859P1 and 7 bits for ASCII7.
We ran csscan and found weird report with exception,telling that some of the data would have 'lossy conversion'. To me it seems that data could be those special chars like 'microsoft word's curly quotes etc..'

Questions -
1. Why the 'lossy conversion' ? when target is the superset of current one ?
2. when it says 'lossy conversion' what does it mean ? will the data will be corrupted for those chars (like upside question marks)?
3. How to fix the 'lossy conversion' data before altering the database character set ?

I am very confused with all of the above...Really need help on how to proceed on this.
Any help would be very much appreciated....

Thanks
Vidya R.