strange cppunit test bug - result that is compared changes when modifying the expected value

Hi *,

make CppunitTest_sw_ooxmlexport

fails on the CentOS 5.9 release-build system because of a weired bug I
cannot quite explain:

fdo66929.docx,ooxmlexport.cxx:1067:Assertion
Test name: Test::run
equality assertion failed
- Expected: 127
- Actual  : 254

line 1067 is:
    CPPUNIT_ASSERT_EQUAL( sal_Int32( 127 ), getProperty< sal_Int32 >(
xFrame, "BottomBorderDistance" ) );

So the test tells that BottomBorderDistance value was not the expected
value, HOWEVER:

I change that line from 127 to 128:
    CPPUNIT_ASSERT_EQUAL( sal_Int32( 128 ), getProperty< sal_Int32 >(
xFrame, "BottomBorderDistance" ) );

and run the test again, and now I get:
fdo66929.docx,ooxmlexport.cxx:1067:Assertion
Test name: Test::run
equality assertion failed
- Expected: 128
- Actual  : 127

So mysteriously now the actual value is the correct/the initially expected one?!

I assumed corrupted ccache, so I cleared that, also used
CCACHE_DISABLE=1 - but neither helped. When I change it back to 127, I
get the initial error again. Actual value is claimed to be 254.

Same behavior when I disable the other value-checks and only have it
check for BottomBorderDistance.

ciao
Christian