Hi anmari, thanks for the reply, and I appreciate your efforts to inform users about this issue. I use a 2Gb Linode VPS to serve just a few WP sites, and I have no other 500 errors apart from the above. I've red your caveats prior to post this issue, but I found no other quick and easy solution than turning off the semi-pagination.
It might be a better solution to create a nofollow rule for all your url parameters, I'd be happy to read a guide on this.