There is no way that I know of that's a "quick and dirty" way to refresh a folder. (Hmm, maybe that'll be part of 10.2?)
However, do go into terminal, and check permissions of files. That is usually the number one reason why you can't see a given file/program/folder etc.
Here's the quick rundown:
1. Open terminal, and navigate to the directory in question. (Let's say the file is bob.html
2. type ls -l
3. You'll see something like
drwxrwxr-x 8 mightyjlr staff 264 Sep 25 09:28 HelloWorld
drwxr-xr-x 4 mightyjlr staff 264 Oct 5 08:50 Tool
-rw-r--r-- 1 mightyjlr staff 695767 Oct 1 12:00 Xquartz.tgz
drwxr-xr-x 4 mightyjlr staff 264 Sep 24 19:03 learningCpp
-rw-r--r-- 1 mightyjlr staff 1475 Oct 4 09:27 macosxpost_10.4.01.rtf
-rwxr--r-x 1 mightyjlr staff 74 Oct 4 09:22 bob.html
4. The important part is the permissions. Those are the "-rwxr--r-x" part of the listing. That's what we need to change (It reads left to right; -=Not a directory, r=root can read, w=root can write, x=root can execute, r=mightyjlr can read, -=mightyjlr cannot write, -=mightyjlr cannot execute, r=anyone can read, -=anyone cannot write, x=anyone can execute.) Obviously we need to change it so that you (mightyjlr) can write, and execute.
5. type chmod 775 bob.html
6. now type ls -l again, you should now see...
(All that stuff before and...)
-rwxrwxr-x 1 twyg staff 74 Oct 4 09:22 bob.html
now, as you see it's still not a directory, root can read, write and execute, mighyjlr can read, write, and execute, and anyone can read, and execute, but not write.
7. Go back to the finder, click where the "missing" file is, and you should be able to see it.
A word to the wise, be careful with chmod. I'm not trying to scare, but somethings are better left alone. (i.e. don't be chmoding mach ok!?)
This is the same problem that I've been having w/ Classic. I'll create a folder/file in Classic, and then go back to X to find the folder MIA....