grab the latest firmware from their forums. The firmware database on the main page hasn't been updated in quite some time.
DD-WRT Forum :: Index
For your router, see here:
DD-WRT Forum :: View topic - Firmware Recommendations - Still 14929 - 02/24/13
As for the language issue, try clearing your browser cache, then refresh the page.
If that doesn't work, you can try switching the language using reference images:
DD-WRT Forum :: View topic - Help - DD-WRT is in Chinese now instead of English
If that doesn't work, try a hard reset:
Hard reset or 30/30/30 - DD-WRT Wiki
__________________
There are two secrets to staying young, being happy, and achieving success. You have to laugh and find humor every day, and you have to have a dream.