This is frustrating.
I have tried many other times and it works always right.

I remember perfectly the steps that I did since it was the first time I launched the environment with the latest alpha version downloaded.

The only unusual thing I noticed is that it didn't give me the usual message "attention this is a beta version etc etc".
But I thought the reason was that I had just launched a beta made the very same day of the previous one, but an hour later (19:xx vs 18:xx)

Soon after I launched a DevPac session and then DOPUS.
I uploaded the IPF from the control panel.
I created a folder in HD1 (a directory in HOST) from DOPUS (which I usually don't do because I create folders directly from the HOST) and started copying the files in IPF disk into it.
3/4 files copied normally, then I saw that the copy didn't go ahead.
I called the debugger and it was looped in the code I posted..

But now I can't reproduce the problem anymore, so I give it up and if ever the system get stuck again I'll let you know :rolleyes

The ROM locations posted is of no help in any way?

Ok, last evening I fiddled with uae.resource and get into a way to consistently crash WinUAE.
I PM you the code, it's not significative and irregular... not that a well written code can crash WinUAE :)

Hi Toni, debug related oddity.

Code:
Before launching the previous one I insert in the debugger:

w 0 dff09a 4 w 7fff7fff.l

Results.
Quickstart A500 (000):

Memwatch 0: break at 00DFF09C.W  W  7FFF7FFF PC=00C077B8 CPUDW (000)

Quickstart A500 (010): save as above
Quickstart A1200 (020): does not trigger
Quickstart A1200, Blizzard 1230 (030): does not trigger
Quickstart A1200, Blizzard 1230 (030, MMU):

Memwatch 0: break at 00DFF09C.W  W  7FFF7FFF PC=47012772 CPUDW (000)

Quickstart A1200, Blizzard 1240 (040, no MMU):

Memwatch 0: break at 00DFF09A.L  W  7FFF7FFF PC=47012768 CPUDW (000)

Cheers.