convolver plays impusle too fast

Another convolver convolver issue ( see other thread )

When loading an I.R file from an alesis midiverb ( tap delay impulse ) , the first part of I.R. file is exactly 169 ms silence , then the firs tap appears at 169 ms
When loading this file into the convolver and feeding it a 1sample impulse ( no looping ) , the first rever tap appears at 122ms …iow 47 ms too soon
No such thing when loading it ito other ir reverbs