I am having huge issues with 2006 (I am just testing right now thank god) I would like anyone out there having similar issues to let me know if and how they fixed it...Here is the skinny (Converting within SW 2006) 1. Set options to System options - Assemblies - Automatically load components lightweight (unchecked) System options - Assemblies - Use large assembly Mode to... (unchecked) System options - Performance - Assemblies - Automatically load components lightweight (unchecked) 2. Open assemblies(s) in question with lightweight unchecked 3. Take entire model and 'save all' 4. Close SW 2006 5. Open SW 2006 6. Open Converted assembly using these options System options - Assemblies - Automatically load components lightweight (checked) System options - Assemblies - Use large assembly Mode to... (checked) System options - Performance - Assemblies - Automatically load components lightweight (checked) 7. 2. Open assemblies in question with lightweight checked At this point the assembly will not open, or take upwards of 45 minutes to open!!!!!! (Converting using Conversion Wizard) 1. Open new folder copy backup of 2005 assembly to it 2. Open Conversion Wizard 3. Open and convert 2005 Assembly 4. (only error reporting 5. Open Converted assembly using these options System options - Assemblies - Automatically load components lightweight (checked) System options - Assemblies - Use large assembly Mode to... (checked) System options - Performance - Assemblies - Automatically load components lightweight (checked) Same result as above, At this point the assembly will not open, or take upwards of 45 minutes to open!!!!!!