Bad pushwall sounds in The Ultimate Challenge

This one is easy to test. Go out of the starting room, move to the end of the corridor that's to your right, and activate the pushwall that's right in the middle, in front of the pool of blood.

If I open VSWAP.SD3 in SLADE 3, SND00013 plays correctly and has a CRC-32 checksum of 23ce1de8 -- exactly the same as in VSWAP.SD2. However, in ECWolf, the pushwall sounds work correctly in Return to Danger; but not in The Ultimate Challenge.