I had the same problem here on 1 test workstation. Lotus Notes and crashes creating a Notes Crash dump file. No Windows event logs are being created. A Lotus Notes NSD Log is created but I have not gone through the with a fine toothed comb yet. There was nothing obvious pointing to the cause at a quick glance. I am yet to go through the Notes DMP file but will do later this week.
I tried repairing Lotus Notes, Uninstalled and reinstalled both products still could not launch Lotus Notes without error message even with out any version of SEP installed. After reinstalling SEP RU6 MP1 problem was still present on the workstation.
So I put it down to the fact that there had been some sort of corruption of the Lotus Notes cofiguration files in the user profile which is where we store the user config for Lotus Notes. In the end I had to delete\remane the Lotus Notes configuration folder on the local workstation to fix lotus notes. For us the path is: C:\Documents and Settings\<USERNAME>\Local Settings\Application Data\Lotus\Notes\Data I renamed the Data folder logged off Windows and back on lauched Notes and was all ok.
I have not done any further testing with RU7. I may have some spare time later this week to do further testing but by the look of it SEP 11 RU7 and Lotus Notes are not going to get along.
Lotus Notes Version Release 8.5.1 FP4
SEP Client Version 11 RU7 For us, we have the Lotus Notes plug in installed but not enabled.
OS Version WinXP SP3