"Invisible" files on /tmp from Flash or Iceweasel?

[Randy Kramer <rhkramer@gmail.com>]

I haven't done much googling on this, I have tried to check some of my old 
notes--maybe I'm a little burned out on google, so I'm just going to ask this 
here--pointers to good google search terms are welcome, I'm just not sure 
I'll find any (where good means terms that give me an answer in the first 10 
to 50 hits ;-)

<background>
In the (older) version of Flash that I used with Iceweasel, the Flash cache 
seemed to be on /tmp, and I could see files on /tmp with names like 
Flashxxxxxxxx.  I upgraded to a newer version sometime in the last year 
(because some youtube videos, iirc, would not work with the older version).

With that newer version, the named Flash cache files are in my home directory, 
within the Iceweasel cache--in my case, in 
directory /home/rhk/.mozilla/firefox/pij0mitp.default/Cache with totally 
meaningless names like B84CDB39d01.  (But that's alright--not the problem / 
question I'm writing about.)
</background>

<leading up to the questions>
The problem I have is that /tmp is still filling up with something, and 
if /tmp gets 100% full (when I have a lot of videos opened (obviously not 
playing--just sitting there and loading so that I can view them when I switch 
to the appropriate tab), the video I'm viewing freezes.  

But, when I go to look for files on /tmp, I can't find any that are related to 
Flash or Iceweasel.  My guess is that somehow Flash or Iceweasel are doing 
something like using an inode to create and use a cache file, but not giving 
it a name, thus I am not able to find such files with the usual tools like 
ls.
<leading up to the questions>

So, my questions:
   * is that possible (that Flash or Iceweasel are using unnamed inodes to 
create invisible files on /tmp)
   * if so, are there some tools I can use to find those files and delete them 
to provide more space on /tmp (to free up the frozen videos)
   * if not, can someone suggest (or confirm) what is happening on /tmp.

Additional clues / confirmation of my problem:
   * After doing a df and finding /tmp at 100% full, I then do things like 
ls -alR /tmp/* (or du -a /tmp) and look at the size of the files there--I can 
see that the named files are nowhere near big enough to fill up /tmp.  (For 
example, with du I see "318     /tmp" meaning that the files that du can find 
total 318 blocks or kilobytes.  My /tmp is 459143 blocks (according to df).
   * If I see df showing /tmp at 100%, I can quit Iceweasel, and the usage 
on /tmp drops down to 1% (to match the 318 kilobytes I mention above).

Thanks!
Randy Kramer