DON'T INSTALL ANY MODS, SPOUT DEVS SAID IT, DON'T ASK ME WHY....
Tutorial in text:
1. Close minecraft
2. Open page http://spout.in/client
5. Download it
6. Click start
7. Type %appdata%
8. Click Roaming
9. Click .minecraft
10. Click bin
11. Open minecraft.jar with winrar
11,1. (optional) Download winrar http://www.rarlab.com/download.htm
11,2. (optional) If you're using 32 bit windows download WinRAR x86 (32 bit) 4.01
11,3. (optional) If you're using 64 bit windows download WinRAR x64 (32 bit) 4.01
11,4. (optional) install it
12. Delete META-INF folder
13. Copy all files from Spout you downloaded to minecraft.jar
14. Start minecraft
15. ENJOY