I've noticed this too.  Haven't tried with other items but TP scrolls definitely seem not to care which slot you're trying to use first.

another item use bug -- the axe that has the ability to silence -- sometimes when you use it it works (ie casts within range), other times in runs you all the way up to the target and then works, other times it runs you all the way up to the target and doesnt work .

Also during this time ive found that you cannot use another skill to interupt, you must use walk command to interupt the silence and then you can use another ability

I 've found that the parasite egg will walk you up to the target and just stop you there.. you are stuck until such time as you die..