I've noticed when using the code-folding from the popup context menu, if you select "collapse functions/methods", or just "collapse functions", they don't always work. It seems to work sparatically if you select "collpase functions", then select "collapse function and methods". Sometimes you have to do it 3-5 times before they collapse. I'm using v5.0 build 5023.

They are working fine for me.
When you say "collapsing doesn't work", are you referring to functions/methods with [-] sign on the gutter? or there are no such signs?
Also, what may affect the functionality is listed below:
-you requested code folding op. too shortly after last code change and code is still not parsed and functions are not recognized (no [-] signs on the left)
-you have parser/syntax errors in your code and functions/methods are not recognized as such
-combination of the above.

I'm referring to the context menu popup when you right click in the editor. You have the option to select 'Collapse All Functions/Methods' and similar. There were no errors or anything, I just wished to quickly collapse them all. Maybe it wasn't done parsing the file fully (there were '-' boxes on the left though).