[O] org-mode version 7.7 and very slow rendering of columns

[Leonidas Tsampros]

Hello,

I recently started playing with the following setup for an Org file of
mine:

* Movies
:PROPERTIES:
:COLUMNS:  %35ITEM %5LIST_ORDER(List) %25Director %19Genre %7Year 
%6IMDB_Rating(Rating) %8Watched{X/} %4My_Rating(Me)
:WATCHED_All: "[ ]" "[X]"
:END:
** List 1
** List 2


Each of List 1 and 2 have around 200-300 children entries each. In plain
Org-mode with no columns mode activated, the tree renders just fine with
noticable delays.

However, as soon as I turn on columns mode I have to wait around 15secs
to get it activated. In the meantime emacs' CPU usage skyrockets to
100%.

After that, moving the cursor between the children entries of List 1 and
List 2 is also extremely cumbersome as each move seems to send emacs to
100% CPU for a little bit.

With debugging on, and during initialization of org-columns, I got this
backtrace each and every time:

  org-up-heading-safe()
  byte-code("address@hidden
  byte-code("\300\301\302\217\207" [nil (byte-code  "bytecode....!$
  org-get-tags-at()
  org-entry-properties()
  org-columns()

Do you have any idea of what's might be causing this hiccup?

Best Regards,
Leonidas Tsampros