I believe it applies to traps, single-use traps, and all variants of teleporters / receivers. It's been a known issue since forever, but was never fixed due to the risk of breaking existing levels. The plan was to fix it with the NeoLemmix V2.00 update, but with that project being dropped... yeah, I probably need to fix it at some point. Looking back, the "it might break existing levels" hasn't really prevented physics changes in the past (eg. the bomber asymmetry fix somewhere around V1.30n), so perhaps the right thing is to just fix it ASAP.
EDIT: I think the best idea is to just get this fixed as soon as possible, so that people can address this if it affects their levels at the same time as updating to use PNGs. Also - it does not affect receivers, only teleporters and traps (including the single-use variety).