limit on number of content placeholders(which are editable in content pages) in master page

[nemesis.saurabh]

hi,
i am using VS 2005. i have created a master.master.
i have added 2 content placeholders, i am able to edit them in the
corresponding content page
but if i am adding anymore placeholders in master form, newly added
placeholders are shown as "master content placeholders" and i am not
able to edit them.
regards,
saurabh