According to Lotus, Netscape 7.0 on Linux is, indeed, a supported platform of iNotes. As of 6.01, anyway. See following for more details:
http://www-3.ibm.com/software/swnews/swnews.nsf/n/jmae5hshj5?OpenDocument&Site=lotus
No, I haven't tried it myself.
Cheers,
- Mike