This is a peculiar problem, which is not really a problem, but is a price that a developer has to pay for object oriented programming structure. because there may be another page in the system, that defines similar hierarchy of the elements, and uses the same names, the .Net framework, gets sort of confused which ones to load and what priority does it have.
for me it was a case, because i used to derive another page and name it as xyzTest.aspx instead of xyz.aspx thus having a work around for not messing up the working code, and can return to the original settings without worrying about which version to roll back to from the source safe. this technique works fine, but when i tried to publish the project, it gives out this error. apart from publishing, there is no error or warning that gets fired off, but strangely the publishing does not succeed! after reporting this to a couple of forums, and trial and error methods, i have found this to work.
still not sure if this was the reason for this error, so any one who has a alternate reason, can post a response.