Just wanted to alert you all to a useful tip for those of you who may be finding random students and/or teachers missing from a class. When this type of thing occurs it is often the result of a caching issue and can be easily resolved.
1. First, go to the 'Class Info' tab within the effected class and scroll to the bottom of the page.
2. Then simply select the option 'Refresh class information'.
Hopefully this will solve the problem. Should the problem still remain however, please log a ticket with the TD Help Desk as usual and myself or Greg will investigate further.