By this point I've created hundreds upon hundreds of eLearning projects using Captivate. In all that time, Captivate has remained very stable for me (very few crashes and zero corrupt projects). Nevertheless, I've received some emails over the last few weeks from Captivate developers who were having issues with Captivate crashing, running slowly or otherwise behaving erratically. In the vast majority of the cases, the following resolved the issues.
Editing over a network drive: Captivate projects simply cannot be edited over a network drive. Backing up your projects to a network drive is a great idea. But if you open a project and then proceed to edit it over a network drive, the project will behave erratically, work slowly and, sooner or later, become corrupt. Take my advice (and the advice of any developer who has lost a project), stay clear of your network drive. If your project is currently on a network drive, first copy the project to your local drive and then edit it.
Run as administrator. If you are using Windows Vista or 7, and you are working locally but Captivate is still behaving badly, try running the software as an Administrator. You can Captivate as an Administrator by right-clicking the Captivate application icon and choosing Run as administrator.
Virus Scanners: Many virus scanners scan your hard drive 24 hours per day, 7 days per week. The scanners are well-meaning but can rob your computer of performance and block all kinds of processes... even Captivate processes. I'd suggest stopping your virus scanner while you're working within Captivate. Instead, schedule the virus scan during hours when you aren't asking your computer to perform intense processes (like producing a Captivate project).
Clear Captivate's Preferences: If Captivate is performing strangely, you can delete the Preferences folder and see if that shakes things up. Close Captivate, find the Preferences folder on your computer (see below) and then restart Captivate. The Preferences folder will be recreated when Captivate starts. If you are nervous about deleting the Preferences folder, make a backup of the folder first and copy it to a trusted location. Then delete the original.
Note: The Preferences folder won't be actually be called "Preferences." Instead, it will have the same name as your version of Captivate. For instance, since I have both Captivate 5 and 5.5 on my computer, I have two Preferences folders, one called "Captivate 5," the other called "Captivate 5.5."
Here is where your Preferences folder can be found (it's a bit different dependent upon your operating system and version):
Windows 7: C:\Users\[user name]\AppData\Local\Adobe\Adobe Captivate
Windows XP: C:\Documents and Settings\[user name]\Local Settings\Application Data\Adobe\Adobe Captivate
Mac: /Users/[user name]/Library/Preferences/Adobe Captivate
See also: Captivate's Cache Feature