[Logic] Problem with FILTER and userfields?

[Ray, W2EC]

I'm using version 6.0.101 and seem to have run into a problem, unless I
don't understand the use of the EMPTY filter option.

I have a userfield defined as GERATOL for tracking these award numbers.
Out of 4,678 entries in my log, only 622 contain GERATOL numbers in the
userfield.

I go to FILTER and select (User)GERATOL with the NOT and EMPTY options
so I can display only those log entries which contain GERATOL numbers.

When I run the COUNT (4 vertical and one diagonal stroke button), it
came up with the expression and 0 records found indicating to me that
there are no records that have data in the GERATOL field, in other
words, all log entries have a blank GERATOL field. I can scan the log
visually and see that there are indeed log entries with data in this
field.

Likwise, if I run the FILTER and select (User) GERATOL and EMPTY option,
it comes back with 4,678 which is the number of QSO's I currently have
in this log. I do have 622 entries containing  GERATOL numbers (as
shown by LOGic 5) so again, it would appear to indicate that no log
records contain GERATOL data.

Now, if I click on the actual display FILTER button (the FUNNEL), I get
a window that pops up momentarily that says "searching", but then an
error window pops up that says "Missing Expression", cancel, ignore or
help. Clicking oh Help does nothing. Clicking on Cancel shuts down the
LOGic session. If I click on Ignore, I get another error message {Error
1925"Unknown member FILTERBUTTON." has occurred in program
_0MT0V4O0E.SETFILTER, line 108.

Another intersting point:

I can run FILTER on original (non-userid) fields ok, until I get one of
the above filter errors trying to filter a userfield. Then, if I try
to go back and run a FILTER on a non-userfield, it sometimes (not
always) fails in the same way. Once the failure occurs on a userfield,
it seems to propogate to occasionally failing on non-userfields as well.

What is the proper way to run a filter on a non-userfield and why
won't the filter pick up the fact that some of my userid fields do
contain data?

Has anyone seen this error or am I doing something wrong? 

73, Ray  W2EC