I have a VB6 application and for 1 action it has to connect to an Oracle db. It has worked fine since years (more than 5 years). Now we have 2 users that have problems.

The error we receive is :
Run-time error '-2147467259 (80004005)': ORA-01019: unable to allocate memory in the user side.

First only 1 user had the error. Since her pc had only 2GB of RAM and most pc's have 4GB, we put 2GB extra in her pc. Afterwards the application worked fine.
The next day she has the same error again. A collegue of hers tried it also and she receives the same error (this person is only backup so she doesn't use it al the time)

Since the query we are trying to run is quite large, I changed the selectioncriteria so that we don't receive so much records. But it still doesn't work.

But then we found out that the error doesn't come when when we try to open the query, it comes when we try to connect to te oracle db.

My connectionstring is :
Provider=MSDAORA.1;Password=pw;User ID=user;Data Source=AXIBI;Persist Security Info=True

Then we have a file named tnsnames.ora on the pc which defines to wich server the connection has to be made. This is the content of this file :
(ADDRESS = (PROTOCOL = tcp) (HOST = servername) (PORT = portnumber))
(SERVICE_NAME = AXIBI.prod.root.int)

This has always worked and now 2 users have a problem with it. On 2 other pc's it stil works fine.