Queries :: Less Than Parameter In Query Works Except When Value Is 100

I have a query that checks a table where there's a field that only has numbers from 0 to 100 (a grade), let's call that field "average" (note, the values 0 to 100 are actual numeric values, not percentages)

here's the problem:

when I filter the query using a parameter like <[value] on the average field, the query does show the expected records that have an average value that is less than the value that I input when prompted... except that it also includes the records on which the average field is 100 ... ... for some uknown reason.

to clarify:it won't show anything over the imput value, it just shows anything under the value I imput (good) and anything that has an average of 100

when I hard code the value for the parameter say <65 the query gives me the results expected (anything less than 65 in the average field) without including records with average equal to 100

some details:

the average field has this code: Average: CInt(Nz([Grade]))

the query looks like this:

SELECT [All Classes P1 Query].Class, [All Classes P1 Query].[Student ID], [All Classes P1 Query].[Full Name], [All Classes P1 Query].Subject, CInt(Nz([Grade])) AS Average, [All Classes P1 Query].Qualification, [All Classes P1 Query].[Student - Class - Grade].[Class Grading Period]
FROM [All Classes P1 Query]
GROUP BY [All Classes P1 Query].Class, [All Classes P1 Query].[Student ID], [All Classes P1 Query].[Full Name], [All Classes P1 Query].Subject, CInt(Nz([Grade])), [All Classes P1 Query].Qualification, [All Classes P1 Query].[Student - Class - Grade].[Class Grading Period]
HAVING (((CInt(Nz([Grade])))<[value]));

I'm on access 2007