I have magento installed in a subdirectory. www.domain.com/subdir/magento

This site worked perfectly at one point. I changed nothing, until my client said he couldn't login to magento admin.

I logged in just fine from my computer, but on his computer it just redirected back to the magento admin login without an error message and a url that looked goofy like this: 

```
http://domain.com/subdir/magento/index.php/admin/index/index/key/3097210b826ac4a86d7531cb4089c9d0/

```

I thought that his cookies were being blocked, but that was not the case. 

My magento settings were secure/unsecure baseurl: `http://domain.com/subdir/magento/`

```
web cookie path: (blank)
web cookie domain: (blank)

```

After clearing out var/cache, I found that I myself could not login to the admin either, with the same exact issue.

I tried the following settings without luck:

```
path: /
domain: domain.com

path: /subdir/magento
domain: vigrond.com

```

I also tried commenting out those lines in `Varien.php`, but that had no effect either.

My server account is a VPS and it has plenty of free space.

So I'm pretty much lost, wondering why this happened in the first place when it worked before (didn't change anything), and why it's so complicated?

Any help appreciated