Im mining Litecoins with a 7870 with GUIMiner v0.04 and cgminer 3.1.0. Receiving about 330 kHash/s and about 25% stales. (without stratum-setup)

Thought that switching to stratum would reduce stales, so I tried and always get the following errors:

2013-12-16 12:08:14: Running command: "D:\Temp\GUI-Miner\cgminer\cgminer.exe" --scrypt -u user.5 -p xyz -o stratum+tcp://stratum-ltc.kattare.com:3333 --gpu-platform 0 -d 0 -w 256 -v 1 -I 13 -g 2 -l 1 -T  --thread-concurrency 8192
2013-12-16 12:08:14: Listener for "Default" started
2013-12-16 12:09:15: Listener for "Default": [2013-12-16 12:08:14] Started cgminer 3.1.0
2013-12-16 12:09:15: Listener for "Default": [2013-12-16 12:08:14] Probing for an alive pool
2013-12-16 12:09:15: Listener for "Default": [2013-12-16 12:09:15] No servers were found that could be used to get work from.
2013-12-16 12:09:15: Listener for "Default": [2013-12-16 12:09:15] Please check the details from the list below of the servers you have input
2013-12-16 12:09:15: Listener for "Default": [2013-12-16 12:09:15] Most likely you have input the wrong URL, forgotten to add a port, or have not set up workers
2013-12-16 12:09:15: Listener for "Default": [2013-12-16 12:09:15] Pool: 0  URL: stratum+tcp://stratum-ltc.kattare.com:3333  User: user.5  Password: xyz
2013-12-16 12:09:15: Listener for "Default": [2013-12-16 12:09:15] No servers could be used! Exiting.

I have no idea what's going on wrong here. Any help would be appreciated.

Thanks.

Towi