This is just an experiment I want you to try.

Save your report to the file system. Pick up the report in Report Builder. Now deploy it to the server. Do you see the same thing? I am not suggesting this will solve your problem, but just take a look.

I have run into similar problem recently. I am suspecting the database drivers. Have a look here,

http://jayaramkrishnaswamy.sys-con.com/node/2777798

Make sure you look up the last link on the above article.