Just a little information to pass on. We here at CATI tech support have seen a few calls regarding the files opening up with the ‘solid bodies hidden’ in SOLIDWORKS 2010. It has been reported to SOLIDWORKS and an SPR has been identified as SPR 524372. The workaround is to manually go into the solid bodies folder and 're-show' the missing body. There is also an SPR for some bodies showing transparent when rolling the bar back and working on the model. When you roll back to the end the transparency still stays with. You will need to remove it manually until this is fixed. This is SPR 538127. There is no target date as of yet for the fix.