I started to get into podcasts when I was loaned an ipodtouch (which I mostly hated). I tried Canola but it was quite slow, and also had various problems, sometimes not starting up or not being able to play if the wifi connection was changed.

Switched to gpodder and everything's much better. The only thing I've noticed, and I am hesitant to blame it, is that the UI touchscreen sometimes locks up a bit so I can't switch apps, but this is possibly something else even though it's only started happening since loading gpodder.

gpodder definitely copes well with malformed feeds - I couldn't get the Guardian Tech Weekly podcast to work with canola for example, but gpodder does cope.

I don't know if it will help, but what here is what I do:

1. Download podcasts on my Linux desktop using gPodder. Since I subscribe to thirtysomething podcasts, it wasn't feasable to run gPodder on my N810.

2. copy to my N810 via either usb or wireless.

3. Listen using MediaBox, which seems to be a little faster than Canola.

I am seconding bashpodder.
http://lincgeek.org/bashpodder/
It only downloads the podcasts, but I'm sure you already have a favourite media player anyway.
I haven't used it in a while, but you can customise the way it organises the podcasts once they are downloaded by editing the shell script.

(Hello everyone; I'm Robert.)