User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.3) Gecko/20070309 Firefox/2.0.0.3 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.3) Gecko/20070309 Firefox/2.0.0.3 When downloading a file, Firefox creates a placeholder and a .part file, and continually adds to this as it downloads. If this drive/share is nearly full, this can accidentally fill up very easily. In addition, space is wasted downloading to the cache first. Reproducible: Always Steps to Reproduce: 1. Set to automatically download files to an almost full drive. 2. Queue up a bunch of files to download at once. 3. Eventually the limit will be reached, and a number of those files will fail to download. (whereas if you were better informed, you could chose which ones to download instead of arbitrarily failing certain ones) 4. Note also that it leaves the .part files and placeholders there after the error message comes up. Actual Results: It doesn't inform you when your queued downloads are too much, and if it's downloading to the same drive your cache is on it'll waste more space by downloading to both places at once. Expected Results: File downloads should have their space pre-allocated in the .part file and it shouldn't need to use the cache. If anyone needs it done another way, an option should be available to change this behavior. The current system is quite problematic and the fact that most people usually have the space is not a valid excuse. It should at far least know how much space it's going to use and stop the user from downloading past the limit.