Access subform filtering works fine in 2003 but breaks in 2010

I have an Access mdb app built with 2003. There is a search function implemented by filtering. The part in question is a main form that lists Lots (analogous to Orders), and a subform that lists items (analogous to OrderDetails) belonging to the lot shown in main form. There are fields on the form to take user entries and a variant LotWhereCond is constructed from the user entry and when a Search button is hit:

Private Sub SearchLot_Click()
'MsgBox "((" & LotWhereCond & "))"
If LotWhereCond = "" Or IsNull(LotWhereCond) Then
  Me!SearchLotFoundLots = Null
  Me.FilterOn = False
  Me!SearchLotFoundLots = DCount("LotID", "Lots", LotWhereCond)
  Me.Filter = LotWhereCond
  Me.FilterOn = True
End If
End Sub

The main form only shows lots that fit LotWhereCond.

It works fine with MS Access 2003.
Now if the mdb (still in 2002-2003 file format) is opened by Access 2010, when search is used, the main form still shows filtered lots properly but the subform is empty (not showing the the items belonging to the lot shown on main form).

The linked field of course is properly set to LotID, as shown in the screen cap.

What gives?
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Gustav BrockCIOCommented:
Try to print out LotWhereCond and apply it manually as the filter.

Hamed NasrRetired IT ProfessionalCommented:
May you upload a demo database to try on access 2013? Or is this issue is specific to access 2010?
shutterhackerAuthor Commented:
Don't know how to close the question.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Gustav BrockCIOCommented:
You mark my answer as the solution ...

shutterhackerAuthor Commented:
No solution
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft Access

From novice to tech pro — start learning today.