This new error message available tries to fix memory issues such as the Out of Memory error message.The Low Memory Options error message is only available with the updated version of Fireworks CS5.
All Fireworks versions
As a general rule, while working with Adobe Fireworks, if you don't want any crash and error messages (An internal error occurred, Could not render the database, Could not complete your request, etc.) it is recommended that you restart Fireworks every few hours to purge the memory.
Please be aware of 32bit application limitations. Since Fireworks is 32bit application, it is limited to accessing up to 2GB of RAM on Windows. As RAM prices have dropped, you might have a higher-end machine loaded with 8GB or more of RAM, but Fireworks cannot access anything but the first 2GB. Instead of popping up an out of memory dialog box, and risk losing data, we've modified the behavior to bring up a Low memory warning dialog box so you can save and close the document, and delete the old history to free up memory. You may also assign a keyboard shortcut to bring up the dialog box to delete the history and close the document too.
You open the updated Fireworks CS5, and switch back to Firefox before it's loaded to do something else. A few minutes later, you Alt+Tab back to Fireworks and there's a Low Memory Options dialog asking you to Close Saved documents and clear history, even though you have not done a single thing in Fireworks yet. Not opened a document, not created a history.
On machines with a LOT of RAM, the dialog is likely not to appear (since windows memory will be always in large free quantity). For example, once, on my 4 GB machine I did NOT see the dialog when actually Fireworks exhausted all own RAM and became slow and unstable and could not save a file. On my Win 7 machine (4 GB RAM) I never see the low memory warning.
And on machines with low RAM (1-2 GB) the dialog will popup all the time, since Fireworks will "think" machine is low on RAM so it should show warning (and it should not!)...
Why Fireworks estimates/measures RAM AVAILABLE TO WINDOWS? Fireworks should only measure its own RAM use!!!