If button 1 is reassigned on iCade, Right + Button 1 cannot be pressed simultaneously. about imame4all HOT 5 OPEN

I can't replicate this problem. Possibly you need to clear the button setting 
by using Exit and then setting the button.

I've tried everything.   I even completely uninstalled iMAME4ALL and 
reinstalled, being sure all cfg files were gone.  Same effect.

I verified that I still cannot move right and use "button 1" at the same time; 
it does not matter what button is set as Button 1, so I am sure it's not a 
mechanical defect with my iCade.  All buttons do work.

OK, I made an error: it's not any button assigned to button 1: it appears to be 
1st black button on top (from left).  I have gone into Notepad, and the button 
press reports "uf".  Also, when I press Right and press that button in NOtepad, 
I'll see "cufufufuf" (with "c" being the first reported character from a Right 
joystick press.).  So I know that the hardware itself works.

Also, curiously, all other buttons in MAME when I configure them report as 
something like 'JOYSTICK BUTTON 1" or something like that.  But only this 
button reports as "1" only.  It definitely seems like MAME seems it as 
something different.

Try deleting everything in /var/mobile/Media/ROMs/iMAME4all/cfg & 
/var/mobile/Media/ROMs/iMAME4all/iOS & /var/mobile/Media/ROMs/iMAME4all/nvram

When I configure top second from left to "P1 Button 1" on mine in donkey kong 
it says "J1 JB J2 JB J3 JB J4 JB". Your joystick should read "d" when pressing 
right then "c" when it is released.

Tried it, same result.  Top second from left still reports as "1".  Also, I did 
verify that pressing right reads "d" when pressed, and "c" when released, so 
that seems fine.

I also discovered something else that might shed light: if I leave the overlay 
interface on when my iCade is connected, pressing the black button always makes 
the on-screen "START" button light up, even if I go in and change start to the 
first button on the bottom row in both "General" and "This game" control 
settings. 

It seems like there's no way to get MAME to see that button as anything but "1" 
and in addition, to make the system think it's "Start".

Regardless, Thank you for your advice and help!