"There was a lot of confusion the first year, year-and-a-half because it wasn't clear where to go for support," said Daniel Williams, chairman of the . Adding to the problem was that Oracle was upgrading its support site at the time.

Primavera customers also had to deal with "a lot of confusion with salespeople. It was not always clear who your Oracle rep was," he said.

The Oracle acquisition also spelled the end for Primavera's much-loved annual conference. Instead, Oracle welcomed Primavera users to its annual OpenWorld show.

"But it wasn't really the same thing," Williams said. "It was more of [a] sales and marketing type of conference."

In addition, "Oracle wants to sell their software to very large companies," he said. Primavera is used by enterprises, but very small companies as well, Williams said. "That's caused a lot of stress."