I could have sworn I did this before.
The validation rule is as follows:
field1 is NOT equal to field2 (field2 is in repeating table, NOTE: field2 in repeating table is being populated on form load via a web service query)
Throw validation screentip: "Test"
It throws the validation error EVERY time though, even when the value in field1 matches the value in field2 (a field in the first column of the repeating table.
The validation rule is written on the field I want to validate (field1).