The other is that at 4'03 and 4'25 there seems to be a kind of time-slip, in that the first note of the last pair of ascending notes prior to the slight (and very tastefully executed if I may say so) pause sounds as though it is early by half its length. Since it happens both times, it must be deliberate on your part, but it just doesn't sound right. Could it be a misreading, or a faithful reproduction of a mistake in the copy?
I haven't yet checked these times in the recording, but I believe this is a place where Haydn in fact does indicate an fermata at a rather odd place before the 32nds pick up again.
To avoid any misunderstanding, let me assure you that I am not
commenting on the presence or duration of a pause (that's why I said it was tasteful). What I mean is what happens just before
I still haven't found the score (maybe it was a library copy I was thinking of), so I can't give you a bar number, but let me see if I can get my point across without. Leading into the pause in question a certain rhythmic pattern comes four times. Each occurrence of the pattern consists of four pulses (probably of 8th notes, possibly 16ths) of which the right hand has the first two and the left hand has the other two. The right hand's two pulses are always descending and it sounds like the first and second times they're in thirds (E-G to D-F and then D-F to C-E), and the third and fourth time they're in sixths (G-E to F-D and then F-D to E-C). The left hand's pulses sound like ascending octaves, G first time, lower C next, then back up to G, and finally upper C.
If you know where I am, what I mean is that the first of the final two left hand Cs comes too soon after the right hand E-C, by half a pulse, breaking the established pulse pattern, thereby causing distress to the listener's inner metronome. It may well be the case that you're not aware of doing it, but to me it just jumps out.