Actually I had this problem occur at a very awkward time. What happened was I could open up the particular file, but when I went to copy or cut a bitmap it would lock up. I still don't know what happened, but I managed to reinstall Flash, but never went back to that file, but started it over. After it happened with that particular file it happened with the rest of them, too, for some reason. It suggested allocating for ram for more undos, but I certainly had enough allocated to flash. I suspect it might have had something to do with motion tweening bitmaps (which I hate using in flash, anyway). No one else I talked to had ever had problem, and it wasn't a particularly large file, either. However, I use W 98, not NT, so not so sure about that. Anyhow, I suggest making sure you've got enough system resources dedicated to Flash.<br><br>good luck,<br><br>jonathan