kamichama karin problem
1. mirror 1
2. windows xp
3. internet explorer
4. nope, i don't have any other browser
7. i've tried downloading kimichama karin vol 15-21
8. all the volumes that i've tried extracting shows this message "the archive is either in unknown format or damaged"
9. yes, i have... two times.
downloaded 2 of the chapters in that range. Had no problems at my end.
I would suggest Cleaning your cache and cookies, and try again.
It could also be something to do with your connection to the server causing it to time out early. Try again is all i can suggest :)