Akregator has an annoying habit of losing your configured feeds when it shuts down abnormally (as in whenever it's "killed"). It's supposed to have a backup of the file, but it manages to truncate that file too.
However, I've found a second backup of the file,
It contains some binary data at the top, and then appears to have a several different versions of the opml file.
cp feedlistbackup.mk4 ../data/protect_my_backup
[shut down akregator]
cp feedlistbackup.mk4 feeds.opml
[remove the binary data at the top of the file, leaving the XML declaration tag and the <opml>...</opml> section. Remove everything from the first </opml> to the end of the file.]
Just remember, copy the file as soon as you see the problem, if you shut akgregator down, it will overwrite the backup file when it manages to exit properly.
If that "feedlistbackup.mk4" doesn't look right, you can always try to recover the opml file from the list of sites in the archive. However, it won't be organised into folders, and it will probably have all the feeds you have ever subscribed to.