Hi CapFuture, I have the same problem as you. DNG4PS-2 doesnt show anything in the file list. I've tried on 2 computers with various files.
Because DNG4PS2 (and CHDK) setting for IXUS40 has some errors:
RAW file length:
CHDK RAW size = 0x50D750 = 5298000 (it seems correct)
DNG4PS2 expected RAW size = 5160000 (incorrect, therefore DNG4PS2 cannot open this RAW)
Matrix size:
CHDK (camera.h): 2376x1728. But this is incorrect, because 2376*1728*10/8=5132160 - is not equal to CHDK RAW size (529800).
So, pixel count must be 5298000*8/10=4238400=883 * 3 * 2^6 * 5^2 = (883*2) * (3* 2^5 * 5^2)=2400*1766
(we trying to obtain x/y ~ 4/3).
DNG4PS2 expects 2400x1720.
We can also find this values in code (for 1.00K):
ROM:FF92186C DCD 2400
ROM:FF921870 DCD 1766
ROM:FF921874 DCD 2327
ROM:FF921878 DCD 1742
ROM:FF92187C DCD 40
ROM:FF921880 DCD 33
Other values similar to matrix active area.