Calling a R/3 transaction in a BSP

Hello,

we have developed a BSP-MVC application in CRM 4.0 and we're trying to call a R/3 transaction, to do that we are calling a RFC function from an event of our BSP source. The RFC function only call the transaction but it doesn't work (The page cannot be displayed), however if we execute the program in debug mode and we define breakpoints in it, the call stops in each breakpoint and then a R/3 mode with the transaction appears over our CRM program. does anybody know what is the problem? what is the different betweeen debug execution and normal execution?