Hi Nisha,
Try and execute the query generated in below case at the database layer hard coding the prompt values and see if it returns any data other than July 2008, if it doesn't then your focus should be at universe layer or database layer in identifying the reason for this.
"Then when I pull in other objects from other table in the result object of the webi query, the Month & Year returns only July 2008, week number returns only week 27 and so on."
A few probable cases could be as below.
any of the universe object from the additional objects mentioned above is having a hard coded where clause that restricts data to July 2008
any of the universe object from the additional objects mentioned above is coming from a table with self join for data month of July
any of the universe object from the additional objects mentioned above is having a complex join as table1.col1=table2.col1 and table2.month_num=07
hope the above help you narrowing down your issue.
Thanks
Mallik