From the early days of HTML under Unix, folders & files shouldn't have spaces. Today's browsers are forgiving, luckily! I have changed names quite a bit using my FTP application. Cleared cache in browser & ZP, think I cleared databases too. Worked okay for me, and I'm quite new to ZP.
The directory name is not the same as the Gallery or Album name. My directories are all without spaces: subdirectoy/folder on my server is 1997Boston,. But the Album name is 1997 Boston & NYC that I changed in ZP. is that what you mean?
PS: The developers are great but allow for time zone differences. They are good at replying but probably busy too. Doing nightly builds is awsome as it means ZP is always being fixed or tweaked between upgrades.