ODBC driver troubles

Hi all,
I've had a couple issues with the ODBC driver that ships with
Postgres. I am using Access 2000 to link tables Postgres.

Of the two issues, one is small: after I enabled row version in the
ODBC driver - to fix a problem updating certain tables - the column xmin
began appearing in all the linked tables. Is there any to prevent xmin
from appearing but still use the Enable Row Version option in ODBC DSN?

The second is a bigger deal. On certain forms, any time an update
occurs, I get a message that text that was destined for a text type
(i.e., unlimited varchar) field has been wrongfully interpreted as part
of the SQL statement. Say if I had written
'This test string will be inserted into the text field'
I frequently get back error 'the relation "test" does not exist'. I was
able to resolve this issue on some workstations by vastly increasing the
cache size, from 100 to ~10000. Is this a good idea at all? And it
still does not resolve the problem on one particular machine, where the
user happens to write several fields of text of about 400-800 characters?

Does anyone have any ideas on how to address this? Advice would be much
appreciated.

Many thanks,

Eric