Yes speed is pixel's per frame.
Edit,
Ahhh, let me guess what you're doing. you must be creating a path with a certain frame delay that delays exactly one animation sequence and then does something (Deletes spite or raises an event at end of path) Hense you need the exact length of an animation in frames. I think we determined this formula once before and its pretty helpful to have, and lots of games use or could use this. Thanks for figuring it out.
Speaking of which, Bluemonk, if you ever make another 1.4x version I have a few suggestions about sprites.
you should have this as one of the autodelete options "Delete sprite after 1 animation sequence"
Also, let us activate special functions or raise events on any of these autodelete options. I have found this a very hard thing to do with script. (We have a "OnCreateSprite", why not an "OnRemoveSprite"?
There are also several bugs I found dealing with the IDE, but I haven't had time to try to reproduce them. One of them was pretty nasty and closed the application without letting me save my work. If you want me to try to reproduce these before you release another version, give me a buzz.