Anyone experienced a discrepancy between Avis.com & Avis.co.uk?

In summary: I have an account on Avis.com, but was having difficultly applying an AWD. So I set tried and succeeded on Avis.co.uk (after creating a new profile with the same Wizard number). Now the same booking shows up for 30GBP on Avis.co.uk, but 50GBP on Avis.com. Not sure how much to challenge it, just in case they question the D005927.