re :''when I reply to an e-mail and start typing every time I hit the space bar the curser jumps to the end of the e-mail. '' and ''Even when typing this message the "enter" send me back to the beginning of the detail question.'' You seem to be discussing two different issues effecting at least two different programs. # In Thunderbird Write, use of 'Space bar' key jumping to end. # In browser, use of 'enter' key jumps to start. This may not be a Thunderbird issue, but could be a 'Keyboard' issue, Suggest you check out your keyboard: * keyboard sensitivity to see if it is detecting your press on the spacebar as a several presses, hence moving cursor further than expected * keyboard shortcuts * keyboard driver updating. In Thunderbird - use of 'Space bar' If reading an email in the Message Pane and the vertical scroll bar is visible, then using the 'Space bar' will Scroll Down Current Message, then Go to Next Unread Message. If composing in a Write window, Space bar moves one space. 'Ctrl' + 'space' will Discontinue or Remove Text Styles.