A new test which I will edit further as it progresses.
TEST:
Disc = Dreamon Vol.17 (undumped this disc) have multiple copies.
Condition = A few light scratches, never been cleaned aggressively, should be good to read.
Drive = SHD-162D
DCdumper 0.2a - used so that I can compare to 0.4a
Faked my own read from 50000 with cdrwin.
Initial Dump = Section 1-49 all ok.
PASS 2 = Section 1 - read error, Section 2 - 49 MATCHES on all. It gave up trying to read setion 1, will start it again and get section 1 to read.
Re-started, fake read with cdrwin, initial dump section 1 ok, pass 2 matched, dense bin created.
Ran ice.exe all tracks ok (75) errors in last data track (in other words) a perfect dump.
No I will remove Section 2,3 & 4, and re run with 0.4a
TEST 0.4a
removed section 2,3,4 in order to force 0.4a to redump these sections only.
PASS 1 - Initial dump. All ok.
PASS 2 - Matces. On all. But guess what md5's differ from first dump with 0.2a, I already know whats going to happen 
dense bin created with 0.4a
Extracted with ice, and im expecting some errors in the first track at least.
Wrong it works fine, weird. 
The files are not the same though, so it must be some magic going on,
But at least you can relax my tests prove 0.4a works fine, but I don't know why it hang at around section 40.
Will edit to add more as the test completes.
Once I have a good dump with 0.2a Im going to check with ice exe, then im going to manually remove a couple of early bin files, and try to dump it with 0.4a. Hold tight for the results jamjam.
I was busy editting XML monkey files all last night hehe