Could somebody who has a 64 bit processor (Intel / AMD)
For AMD:
boot up with arch=i386 -force64
For Intel:
boot up with arch=i386 patcher_opts=49 -amd -force64
and see if the 64bit Finder (not a decrypted one from Marvin's Utility) runs without those issues.
I am beginning to suspect that the rebasing of the dyld may have something to do with the last bug.
I also think that they are i386 dyld related (not x86_64 dyld)...
I am currently rebuilding a kernel with sysenter trap pre-patched in dyld but not rebased to see if this is the case.
I have also made a decrypt of "Finder" (32bit only though), removed the code signature and packed it with upx to test in case this doesn't work.
Working hard on a final solution...

Please, somebody who can, do me a lot of fun and test it... all for the sake of progress...