Crashes when doing double click on a note twice, and related issues

Hi,

I have Musescore 0.9.6.2 in Ubuntu 10.04 64 bit connected to a MIDI keyboard and an external sound card. It's the first day I use this program and I've found a few related problems at once.
The thing is: I just want to join a chord with a tie to the same chord in the following bar.

Problem 1: I can't do it in Note entry mode. When I am in Note entry and press '+', it says: 'No note selected. Please select a single note and retry operation'. The same happens if I click on the button of 'tie'. So I leave Note entry mode and click on the chord. But even by double clicking, it doesn't select the entire chord, so I have to tie note by note, by clicking on it and pressing +. How can I enter a note with a tie in Note entry mode?

Problem 2 (similar): Why can't I select all the notes of a chord when double clicking on a chord? If one note of the chord is selected and I want to select also the rest of them, how can I do that? (shift+up or down selects the whole bar).

Problem 3 (the big surprise!): I do double click on a note, and after that, again double click, and the program crashes.
By starting mscore -d in a terminal, I see that the last lines before crashing are:
'MuseScore::changeState: STATE_EDIT
exitState
Segmentation fault'

Problem 4 (unrelated, but also strange): Why isn't there any 'Ritardando' in the standard palettes (or anywhere)?

I'm really looking forward to starting using this program properly, but I'm finding many problems in the way...

Thanks a lot for your help!

Pablo A.