Lotus Notes 6.x on Ubuntu 7.04, 7.10, etc
This is not a tutorial, just a helpful hint for those struggling.
I tried for quite some time getting this working.
In short, this is what was causing my issues. I had to reinstall with Default Settings set to Windows 98, NOT Windows XP.
Some tutorials state to set nlnotes.exe or notes.exe to Windows 98. I believe this is because older versions of Wine had different defaults. Try this, and let me know if it helps.
Note: Newer versions of Lotus Notes (version 8 and higher) have native Linux support. A demo can be downloaded from IBM's Lotus Notes page.