If spell check is enabled in the preferences (Eclipse 3.8) and you attempt to fix a misspelled word by using the tooltip suggestion, the ReST editor replaces the misspelled word with the text of the tooltip and not the word. For example, let's say I misspelled "scheduler"
shceduler
If I put my mouse of that, the tooltip would present me with several options:
Change to 'scheduler'
Add 'shceduler' to dictionary
Ignore 'shceduler' during the current session
Disable spell checking
If I click the first hyperlink ("Change to 'scheduler'"), the editor replaces "shceduler" with "Change to 'scheduler'" instead of just "scheduler"
OK I reproduced the bug.
As a workaround, you can try the Hunspell4Eclipse speller:
http://marketplace.eclipse.org/content/hunspell4eclipse-0
Latest commit (95f03ca) fixes this behaviour with the default spell engine.
Closed as fixed version is available online.
Install must be done through the update site, not the marketplace (unknown compatibility error)