Hi Genito...
Are there any events logged in the application event log that gives an idea why the IS isn't starting? Is the IS dependent on the iSCSI service to start, before it starts? We've seen issues where the iSCSI service takes longer to start than the IS...and since the iSCSI service has to be running before your iSCSI connected LUNs can be presented back to the OS, the IS will be looking for data on LUNs that have not connected yet.
During the Configuration Wizard in SME, one of the questions the Wizard asks you is if you want to make the IS dependent on the iSCSI service starting before it starts. This prevents situations like this, where the IS is starting much before the iSCSI service does...and then can't find data...and fails to start.
Let me know if that fixes your issue...
Shannon