We have managed to load Symantec on the R90L (2G Flash /1G RAM).
You have to change the RAM Drive to 99Meg.
Use a memory stick and change your environment variables to point to the memorystick
Install Symantec
Enable Write Filter.
Add the following exclusion in Write filter ( for program and sig updates)
c:Doc and UsersAll usersapplication dataSymantec
c:program filesSymantec
c:Doc and Settingsprogram filescommon filesSymantec
c:Doc and UsersUserlocal settingsapplication dataSymantec
c:Doc and UsersAdministratorlocal settingsapplication dataSymantec
change the environment variables back to z: