Wonder if someone can spot a problem I can't

I'm moving 9 bytes of data to each of two SX18s (@ 50MHz)
from an 18F452 (@ 39.3216MHz) through two 74HC573 latches

http://home.clear.net.nz/pages/joecolquitt/452+573.html

But it appears that the 573s are ignoring the state of LE and
data is changing on the outputs regardless

The white lines show Q0-Q3 of 573(1) and green is 573(2)

AFAICT the conditions for data set-up and LE are being met
so.......why ? LE is flicked low for ~300ns, total time for transfer
of 18 bytes is ~40us

As the SXs have PortBs as permanent inputs I figured the
573 OE could be tied low. The d/s says that OE and LE are
separate functions

The graphic between the yellow lines is how I reckon it should
look - static data (ie last data held) when either the blue or red
LE line is steady

At the bottom of the page is a separate test routine showing all
573 outputs and D0 from F452 PortD. Data gets to Q0-Q7 even
with LE high

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