I don't know if this problem has been already reported, but I see some weird behavior with some simple integrals, this happen when I try different kind of optimizations (symbolic, numeric or none) at the same time I try different kind of fraction convertions(decimal, fracction or auto), when I try the eval function I get the same problem.
I attach a file done in the latest stable version (0.96 build: 4868), showing this behavior.

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Wrong_sign_1.sm (13 КиБ) скачан 62 раз(а).

Confirmed in 096_4909

It seems that wrong result will be when the Fractions: Fraction/Auto and Optimization: Numeric

Regards,
Radovan

The problem is solved by the Maxima plugin. However, currently you need to explicitly let Maxima take over the functions, otherwise the integrals will work the old way.

[EDIT] Adaption to current state of Maxima plugin

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