Just for the records: I also edited the ROM with the two first suggested amendments. The first made the radar flash only now and then, the second was perfect. Thank you for this great patch! I had in mind to upload the patched ROM but I see many things happened over the weekend and that it's no longer necessary.
So far it looks like every Coleco standard release just runs slower in PAL.
Is that correct what I guessed by other posts, that is that PAL Colecovision units run the games 1/6th slower than NTSC units?
For homebrew releases PkK has commented that he checks the 50hz/60hz byte to change speed accordingly, I do same in my games, so music and gameplay are unchanged between PAL/NTSC.