@constantine
Thanks for letting me know, unfortunately I am busy working quite hard at university, both doing university work for my engineering course and also finishing up some applications that need to be completed this week for different events around campus. I did look a bit harder at those apps you mentioned and TBH I am completely confused by how Nokia decided to launch them. Seems like some use the "maemo-invoker" tool so I tried messing around with my DBus overrides for them to detect when they are launched but nothing working yet. I also managed to replicate the bug you're getting with File Manager, that confuses me a lot and it looks like it will take a bit of time to figure out why exactly it is doing that (I really miss .NET's error reporting there).

@linuxnoob
Thanks, makes me feel better about not getting around replying to this thread yet. As for locking the phone when an SMS comes through, I'll take a look but I don't usually get all that many SMSes (use IMs a lot more) and I never remember to check what DBus calls are being made when I do, will try and remember to check next time I get one. Otherwise you are welcome to see if you can figure it out. Just open up a terminal and run "dbus-monitor" before clicking on the yellow popup, then read through the output from dbus-monitor and see if there is anything in there that looks like it is opening the conversations app. If you can find one then PM it to me and I'll add it to the override file. Unfortunately though, if there isn't a DBus call when it is clicked it will make it extremely hard (impossible in my case, since I haven't learnt how to inject libraries) to detect. I guess another method would be to monitor the conversations database to check when the number of unread messages decrements and lock then, but that would probably aggravate people whenever they clicked on a new message in an already unlocked conversations app.