Thanks for the link tin. Interesting reading. My mobo (2B) worked fine with Blizzard 1220/28, but experienced constant lock-ups with ACA 1230/28.
I removed only E123C, E125C as recommended and the lock-ups are gone and the card & amiga seems to work reliably and stable.
But I discovered minor problems with the parallel port (printing is ok, but connecting my 1541-II with par port cable for transfering data does not work anymore - it freezes amiga), so maybe it should get better if I do more fixes described in the link you provided.