Can the Tiptronic ATF get contaminated with diff lube?

[Dale_K]

I have seen a 0740 code in my 2000 S Tiptronic, which is identifying a problem with the lock up clutch on the torque converter (I think). It has been suggested to me that one possible cause is that the Tip fluid could be contaminated by diff gear oil and that high mileage Boxsters are succeptible to this. I can see how contaminated fluid might affect anything in the tranny with a clutch but it seems more likely to me that any cross contamination would go the other direction and you'd see ATF in the diff.

I guess a lab analysis would clear this up once and for all but I thought I'd ask whether anybody has real world experience with contaminated ATF. The shop manual seems to indicate it could happen if you pulled one of the axles without draining the diff first. Can it also happen if you had seals leaking on both the diff and the tranny?

I'm probably going to get the Tip serviced and fluid replaced with new and I hope it puts the 0740 code to rest.