current transaction is aborted, commands ignored until end of transaction block

Hi:

After upgrading 7.4.2 to 7.4.5 quite smoothly in a Red Hat 8.0 box, we
are having intermitent issues with certain online PHP transactions,
returning this error:

"Warning: pg_exec() query failed: ERROR: current transaction is aborted,
commands ignored until end of transaction block"

Half the times we run the query we get the error, the other half it works.

Any ideas? Thanks.