B737-700 IRS POSITION ERROR

[flyday]

Hi,
after 11 hours flight, we had L/R IRS position error as:
FMC POS, GPS L/R POS: N24/32/6, E118/07/9
IRS L: N24/32/3, E117/59/1
IRS R: N24/30/9, E118/10/1

The pos error for L/R shown on CDU are 6.9/3.6nm.

I know there are well below the AMM 34-21-00 limit for individual system.
However, this L/R DIFF cause the FMS message: VERIFY POS IRS-IRS.

Does anyone know where to look for the limit for difference?

Cheers,

[flyday]

Upload the screenshoot.

Any mate to give some advise?

I reckon replace R adiru can solve the problem if next flight occurs similar msg again.

But that is not the prefer solution so far...

[motortek]

just check door drains maybe door drains are leaking water this water flows into adiru

[flyday]

Update:
Fault doesn't occur in the following 11 hours flight.

[flyday]

[motortek]

[flyday]

Thanks Motor.
not in this case anyway...