Features compile but don't work

In my current font project (a cursive conscript*), I have added the OpenType features [aalt], [init], [medi], [fina] and [liga] (along with the usual [kern]). These features compile without any errors and appear to work properly in the OpenType Features tab of the Preview panel (they don't preview properly on the Preview tab, but I've read elsewhere on these forums that [init], [medi] and [fina] don't preview at all in FontLab Studio, but still work in applications), but when I generate the font (as a .ttf), none of them work in the applications I use this font in (Photoshop and Word '07-'10). It's as if they're not there. However, they appear in the relevant tabs when I open the .ttf in Studio, exactly as they are in my project file.

I read in another topic that Studio 5.0.4 doesn't work on 64-bit Windows Vista (which I use), but I want to be sure I haven't done something wrong in writing the features before I ask about replacing Studio 5.0.4 with v5.0.2. Your help will be much appreciated.

I should mention that I'm a font creation newbie, not a professional. There's plenty I don't know about making fonts, especially ones with OpenType features. There's a pretty good chance I didn't perform a key action (like maybe setting types for each glyph?).

*I.e. a constructed writing system