I switched to the LAE gradebook after issues with the vanilla gradebook not lining up when student column was made static.
Recently, it has been temperamental by not saving grades input into it and being agonisingly slow.
Going back to the vanilla gradebook with Ajax turned on also allows grades to be input even with editing turned off. Should this happen? Regardless, it has been the best and fasted solution so far.
How many students and how many grades? Make sure your max_input_vars in php.ini is at least 20,000. This can be the only cause for not saving grades.
LAE Grader is somewhat slower than Grader because of what it does. I usually recommend setting students per page at 25 or less. I can run a course on my site with 525 students in it and load in about two minutes with all students on one page but I have a very strong server.
Make sure you have the latest version.
Moodle 2.8 will come with a new grader that scrolls both directions and doesn't lose column headers or student columns. Out around October, 2014.
We only had 8 students in as a test run through. Had approx 100 grade items.
Not had this problem before. Looking to upgrade from 2.5.3 upwards after the next academic year. Unfortunately, I inherited the site with a custom theme and apparently upgrading will cause issues with the theme. Looking at it doesn't look particularly difficult.
Latest version of LAE Grader