hi ,
I noticed a funny thing,

What i did was, i deleted a datafile belonging to users tablespace
manually at the OS level.

Then i created a tabe in that tablespace, which works fine; even
though the underlying datafile is missing;

Then i insert some rows....and commmit...ok it works fine...

then i switch logfile...then also it works fine.....

then i shutdown the database normally, then also it works fine.

Then problem occurs only when you shutdown and restart the database.....
why it is so ?