A DL error and a feedback error

I have two problems:

1. Whenever I DL a model or skin now, it's empty, and when I try to extract the files, it doesn't work.

2. I can't post anything on the model pages to give feedback or whatever, it says I'm not logged on.

Can someone help me with these?

1. Save-as and don't just open them from your web browser.

2. Log in.