Ipod classic - crashes during songs

[pequetc]

So i have succesfully installed Rockbox on ipod classic (classic -1st gen, or 6th gen of ipod). It worked perfectly, but recently im having this issue more and more often.
The thing is, that when I listen to a song, sometimes, it just crashes and all i can hear is high single sound, very unpleasant. Ipod is stuck, only reset (menu + middle button) is working than.
I don't know whether it's problem with rockbox itself (said to be unstable on classic, aware of it) or rather problem with ipod's hard drive? If drive is the cause, can u suggest something (formatting, defragmenting)? I would be thankful for every piece of advice u can give, as i don't know much about these things.

Best regards, pequetc.

[saratoga]

What version are you running?

[pequetc]

From rockbox info, version: r31516-120101. Need emCore version as well?

Edit: many thanks for solution, i'll try updating but i'm quite positive that it'll work.

[amayer]

that build is 9 months old and Very buggy.
you can get the most recent build here:
http://build.rockbox.org/data/rockbox-ipod6g.zip

I use these builds daily and only encounter crashes when trying to do something dumb.

Just extract the zip file to the root of your ipod(or extract to your computer and copy the files to the root of your ipod)
you may need to enable "show hidden files" depending on what operating system you are useing