I don't get it.
I have the Virgin media (uk) scientific atlanta explorer 8300dvb too.
I've been using my pronto to switch it on/off for years.
This is the code in the pronto:
5000 0000 0000 0001 000A 000C
Now I've just bought a USBUIRT and am trying to paste "long" hex codes into eventghost.
As suggested above I am using makehex with rc5.irp and Device 10, so my irp looks like this:
Device=10
Function=0..127
Define T=0

Protocol=RC5
Frequency=36000
Time Base=889 '888.89 = 32 cycles at 36Khz
Message Time=128 '128 times TimeBase
Zero=1,-1
One=-1,1
Prefix=1 'Officially -1,1 but starting with off is silly
First Bit=MSB
Form=;*,~F:1:6,T:1,D:5,F:6

The created .hex file contains this code for function12:
Device Code: 10 Function: 12
0000 0073 0000 000F 0040 0020 0020 0020 0020 0040 0040 0040 0040 00C0 0020 0020 0020 0020 0020 0020 0020 0020 0020 0020 0040 0020 0020 0040 0020 0020 0040 0020 0020 0AC4

But this does not work !
I used eventghost/USBUIRT to learn the power on/off button. The learned code is here:

0000 0074 0000 000A 0020 0021 0040 0021 0020 0041 0040 0041 0040 0021 0020 0021 0020 0041 0020 0021 0040 0021 0020 0C90

So what have I done wrong ?
I want the long hex codes for all the buttons.
I know I could just learn all the other codes, but where's the fun in that ?