nis2 dev kit sdram verify failed

I am using Nios2 dev kit(cyclone2), and quatus8.1,

could rebuild sopc and compile example nios2 standard project successfully.

but encountered the following problem when run sample application

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Downloading 02100020 ( 0%)

Downloading 04000000 ( 0%)

Downloading 04010000 (65%)

Downloaded 98KB in 1.7s (57.6KB/s)

Verifying 02100020 ( 0%)

Verifying 04000000 ( 0%)

Verify failed between address 0x4000000 and 0x400FFFF

Leaving target processor paused

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I've found there is some post about verifi failed problem,

but that seems because of customized H/W,

I just used altera dev kit and sample project.

so is it physical H/W problem?

Could someone help me ? Thanks!