Say you have turned off images and say you are filling an application form , now in order to submit it you are requested to type a series of alphabets from an image , now here begins the problem you go to the required option and enable images and then what you will have to reload the entire page for doing this and when you reload the page you lose all the data that you have filled up. you could also try right clicking the place where the image is and selecting view image but now the image opens as a next window and when you go back you loose all your filled data.
Sea monkey also is a very good browser . In opera when a particular page is navigated away the contents that you filled in the page remain intact as you typed it because opera loads pages from the cache to save time.
Another feature which should have been incorporated in Mozilla is the ability of to block various advertisements and pictures from servers.(Opera has this functionality though)
Another feature which should have been incorporated is the ability to download from torrents .Opera has an inbuilt bit-torrent installed in it.
Other applications such as Mail and newsgroup , IRC chat, and address book are some features which could make Mozilla an ideal browser.
Seamonkey and opera has mail and news group, chat and an address book inbuilt in it so you should some day try it.
These advancements to be incorporated in Mozilla can be rectified by adding addons for Mozilla FireFox . Still ,it is one of the most powerwul browsers out there.