LMMS Broke my ALSA?

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Running Ubuntu 10.04 with LMMS 0.4.5. I was playing around with different instruments that come with LMMS, as well as with soundfonts. Everything was working fine, but eventually, the sound started stuttering heavily. It sounds like some kind of buffer underflow issue. I didn't think much of it and went to sleep, but when I booted my computer today, the problem was still there, except it doesn't just affect LMMS, it affects everything else on the system as well!

It really seems like something in LMMS, or a plugin LMMS uses, corrupted my installation. I really don't see what else could have caused this. I'm using LMMS with ALSA, nothing peculiar in my audio configuration as far as I know. As a programmer, I would question whether or not it's possible that LMMS, or some plugin it uses, reduced the some buffer size somewhere in the ALSA configuration, or did some other similar manoeuver to try and get better sound output latency, in a way that affects the whole system.

Things I tried so far:
- Increasing the LMMS buffer size
- Reinstalling pulseaudio

No success in fixing the problem at this point. Any help would be appreciated.
Just an update to say that reinstalling ALSA seems to have fixed the problem for the time being. I'll let you know if it presents itself again. On a side note, LMMS crashed on me a couple of times while I was tinkering with it last night. Do you guys think the latest version is more stable than 0.4.5?

I also wanted to say that despite its few glitches, I'm really liking LMMS so far. Nice and intuitive GUI design, very good set of features. The list of FX plugins and presets included is also very impressive.