What problem are you speaking of? As I previously said, if I've consumed ethanol (even a few beers), the 1,4-butanediol produces no effect whatsoever, which is consistent with the hypothesis that 1,4-BD itself is not active.
Next would be to actually do a more controlled experiment and take 1,4-BD after consuming non-intoxicating (as opposed to ethanol) 1) alcohol dehydrogenase (ADH) inhibitor or 2) aldehyde dehydrogenase (ALDH) inhibitor. I have a feeling that it may be the 4-hydroxybutyraldehyde responsible for the unpleasant side-effects of 1,4-BD, so if this hypothesis is correct, then taking it after ADH inhibitor will not produce any effect, while taking it after ALDH inhibitor will produce the nasty side-effect.
Another thing I've been considering is the fact that both GHB and phenibut are GABA-B receptor agonists, as opposed to benzos and ethanol, which act on the GABA-A receptors. I have taken phenibut quite a lot and I noticed that in higher doses, it produced these weird involuntary movements of fingers. The same effect is observed after taking higher (3-4 ml) doses of 1,4-BD, which makes my fingers move involuntarily a lot, which makes typing really hard for example, because I keep pressing buttons without wanting to do so. This led me to think that maybe there's something wrong with my GABA-B system, because phenibut wasn't all that pleasant for me either, as is 1,4-BD.