Which game including Game-ID?
Which type of controller?
Which kind of setup are you using?
Softmod, Hardmod, Nomod?
How do you start the game (OPL I assume)?
Which version of OPL are you using?
Where are you starting the game from?
The pad type shouldn't matter.
It is a common behavior with many games when playing from SMB or USB.
Then the controller probably doesn't support transmitting all buttons at once.
Never thought it could be related to the pad
But, the SAME combination works fine in POPSTARTER.
Maybe the transmitter causes the pad-init to stall after an IGR from OPL.
His other receiver working with the new pad