Platform and OS info below, should have included before. The tpl files are in the correct location and are fine. The feature has worked fine for me in all other builds. I can't check if I can add snippets because I have reverted back to 1640.
DevEnv.exe version 9.0.21022.8 msenv.dll version 9.0.21022.8 Font: Courier New 13(Pixels) Comctl32.dll version 6.0.2900.2982 Windows XP 5.1 Build 2600 Service Pack 2 Single processor
Can you post the full directory name where you are seeing the tpl files please. Does this path contain any extended or Unicode characters? Paths containing Unicode characters stopping Snippets from working is fixed in VA 1645, so I am wondering if this fix is related to your problem.
Can you run filemon, filter it to show activity on the tpl files please: