The findings were released last week at the start of the user group's annual conference in Birmingham.
After questioning more than 500 users, the OUG found a 12% increase in satisfaction compared with levels expressed in its 2003 survey.
Ronan Miles, who chairs the user group, said the results were encouraging, but added, "There are still details that can be addressed, such as support, which is lagging behind in terms of customer satisfaction."
Users called for simpler installation of Oracle's 9iAS and AS10g application server software, although some respondents acknowledged that Oracle had made some improvements to installation procedures in the past year.
The perceived cost of using Oracle products was, once again, highlighted in the survey. Users felt that Oracle products were more expensive than the rival Microsoft SQL database server.
Some respondents also indicated a growing awareness of MySQL, the free, open-source database alternative to Oracle's flagship products.
The survey revealed some user frustration with Oracle's consulting arm, with 22% of respondents reporting unhappiness, particularly on value for money.
Miles said that frustrated users were probably spending money on Oracle Consulting services, "to dig them out of holes" but would prefer to use their budgets to help with business change projects.
Another area of concern was the escalation of support queries when a problem could not be resolved easily.
Of the 448 respondents, 125 were happy with Oracle's support escalation process.
But of the 197 respondents that had used the service, 37% reported that they were unhappy with the response.
Commenting on support escalation, Jean Reiczyk, Oracle Europe's services vice-president, said that 65% of support calls were based on users' own configuration problems rather than problems that were inherent in Oracle products.