3 troubles with ardour 0.99.3

Hi everyone.
I experience some troubles with ardour 0.99.3, and I’d be very pleased to get some help from you.
The 1st problem is that ardour sometimes crashes with segmentation fault.
The second one is that it from time to time disconnects from jack, and the only way to reconnect it is restartiing, that is very annoying.
And the last trouble is very rare, but very sad. Sometimes is sais that the prokect doesn’t have a click session. Consequences are very unpleasant: I have to rearrange inputs and outputs for every track and assign plugins for every track.
My configuration is: athlon 64 3000, 512M ram, s/b audigy.
If somebody knows the solution to these problems, I’d be very pleased to get some help.
Thank you.