commit fails for big files

if I commit large files bazaar buffers the data for performance reasons to the system memory.
If this exceeds 2GB memory it does not work.
for standard sourcecode applcations this should worl fine but for bigger files (even videos) there should be some streaming features...

Committing to: E:/temp/bazaar/
added robots
added robots/#auto_convertedTV
added robots/#auto_converted_webmp4
aborting commit write group: MemoryError()
bzr: ERROR: exceptions.MemoryError:

Traceback (most recent call last):
  File "bzrlib\commands.pyo", line 729, in exception_to_return_code
  File "bzrlib\commands.pyo", line 924, in run_bzr
  File "bzrlib\commands.pyo", line 560, in run_argv_aliases
  File "C:/Programme/Bazaar/plugins\qbzr\lib\commands.py", line 728, in run
  File "bzrlib\commands.pyo", line 924, in run_bzr
  File "bzrlib\commands.pyo", line 560, in run_argv_aliases
  File "bzrlib\builtins.pyo", line 2932, in run
  File "bzrlib\decorators.pyo", line 192, in write_locked
  File "bzrlib\workingtree_4.pyo", line 226, in commit
  File "bzrlib\decorators.pyo", line 192, in write_locked
  File "bzrlib\mutabletree.pyo", line 228, in commit
  File "bzrlib\commit.pyo", line 363, in commit
  File "bzrlib\commit.pyo", line 648, in _update_builder_with_changes
  File "bzrlib\commit.pyo", line 860, in _populate_from_inventory
  File "bzrlib\commit.pyo", line 904, in _record_entry
  File "bzrlib\repository.pyo", line 502, in record_entry_contents
  File "bzrlib\repository.pyo", line 831, in _add_text_to_weave
  File "bzrlib\knit.pyo", line 913, in add_lines
  File "bzrlib\knit.pyo", line 923, in _add
MemoryError

bzr 1.15 on python 2.5.2 (win32)
arguments: ['filenames removed"']
encoding: 'cp1252', fsenc: 'mbcs', lang: None
plugins:
  bzrtools C:\Programme\Bazaar\plugins\bzrtools [1.15]
  launchpad C:\Programme\Bazaar\plugins\launchpad [1.15]
  netrc_credential_store C:\Programme\Bazaar\plugins\netrc_credential_store [1.15]
  qbzr C:\Programme\Bazaar\plugins\qbzr [0.9.9]
  svn C:\Programme\Bazaar\plugins\svn [0.6.1]
*** Bazaar has encountered an internal error.
    Please report a bug at https://bugs.launchpad.net/bzr/+filebug
    including this traceback, and a description of what you
    were doing when the error occurred.