For JDBC tables, CONNECT calls a Java wrapper and if an error occurs, retrieves the Java error message and displays it. In this case it can be a bug in the Jtds driver, in the Apache pooling process, or simply that the Apache pool does not support all drivers, or even that this is an error which is platform dependant. In any case I would not rate it as Major since it works normally with the JdbcInterface wrapper, which by the way is currently the only one distributed with binary distribution.
Sorry about the Major priority rating. I accepted the default but have now changed it.
On a related (sort of) note, can you think of why when using the Microsoft provided JDBC driver the table names would come back as blank? I haven't posted anything here as I figure we must be doing something stupid. There is a row for each table name, and the open source jtds driver returns the table names correctly, but the MS JDBC driver has blank table names. I'm guessing this is some kind of character encoding problem as the numeric columns come back fine.
Also, possibly related 
is that foreign chars (say Japanese chars) INSERT and SELECT fine, but if you update they get replaced with ???. Because they work on INSERT and SELECT but UPDATE messes them up, I am wondering if its a CONNECT string parsing issue?
Works perfectly using MySQL jdbc with both local and connect databases using UTF8 if that helps.
I'll been busy for a couple of days and look at these problems when I come back. Thanks for reporting.
Any update on these?
This is an older bug report that has superseded by others. This bug can be closed as a duplicate (even though the duplicate is newer than this one.)