[Opensource] Expresso DBObjects - Serious error in caching or something else?

[Gabor Nagypal]

Hi!

I use Expresso 5.0.5 and I have the following problem:

I have a DBObject, let's say MyDbo, which has an attribute "id" as DB 
key, and "dummy", which can be null.
I have a raw in the DB where the attribute "dummy" is null. Let's say 
the is for this raw is '1'. Now:

DBObject dbo = new MyDbo();
dbo.setField("id","1");
dbo.retrieve();
dbo.isFieldNull("dummy"); -> gives back TRUE
DBObject dbo = new MyDbo();
dbo.setField("id","1");
dbo.retrieve();
dbo.isFieldNull("dummy"); -> gives back FALSE (with getField I get an 
empty, but non-null string)

So what happens: I read the same row from the DB in one application, in 
one thread. I do not change the DB between the two read operations, I 
use a new instance of dbo to avoid any interference. However, for the 
first time Expresso says that the attribute "dummy" is null (which is 
right) but for the second time it says the field is not null.

What is that? Do I miss something here, or is it a critical error in 
Expresso caching code?

Anyway: I use PostgreSQL as a background DB...

Regards,

Gabor