Problem with overridden instance of CI

[eluser]sangharsha[/eluser]
I have a plugin which needs database access. To get this, I have used the get_instance() of CI.
With the new instance thus created, I could make database queries.

But once I created this instance, the original instance of CI was overridden. And hence
this triggered another problem: the original instance of the CI object gets lost, and the subsequent calls to $this->db->query() doesn't work anymore.

And again I have to call the get_instance() to make the queries. Is there any way to restore the previous object?

See this conversation for details:
http://ellislab.com/forums/viewthread/59083/

Any help would be appreciated.