"ORA-00942: table or view does not exist" when deleting from a very real table in the user's schema
Once I had a similar Problem. To shorten a rather long story, just flush your shared pool.

ALTER SYSTEM FLUSH SHARED_POOL;


Somehow Oracle seems to create an corrupted entry in the statement cache. Problem has been resolved after flush. After that, we were unable to reproduce it.

You need some administrative privileges to flush it.

One final note: ORA-00942 does not exist in the database documentation at all.

According to my notes, we used this Oracle version. 

Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production