Unexpected crash on target platform on S60 phone

Everything seemed to work fine under my emulator with new S60 FP1 SDK. But when I tried a build on release target platform, it worked until the application try to start another process, it stopped dead. Here, I use the gcce build target from the command line.
A solution is "comment out" REL_OPTIMISATION=-O2 -fno-unit-at-a-time in S60_3rd_FP1\Epoc32\tools\compilation_config\gcce.mk. This is a default setting from the SDK but it does not fit for my application.

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