Report parameters doesn't appear correctly

I have a report .rdl under Visual Studio2010 and sql server2008.

the report language is arabic and all the fields appears correctly, but the parameters doesn't appear correct it shows stange characers(not question marks) and all the remaining fields show arabic characters correct.

i run the report on internet explorer9.

i don't know what is the problem, i searched alot and there is nothing new. what can i do??