remote update with EPCS128, the start address can not exceed 0x3C0000?

Hello, Guys.

I have a Stratix II EP2S90 design that uses an EPCS128 device in AS mode for remote system update. I have a factory image and an application image. When the factory image start address is 0x000000, and the application image start address is 0x3C0000 (or lower), it works (both of the images are compressed). But when I change the application image start address to 0x3F0000 or higher, first time the update successes, but all the subsequent update fails(it returns to factory image automatically).

PS: 1. the compressed file size are 0x00F77B0 bytes.

2. I know I can only utilize the first 32 sectors of the EPCS128 device

as configuration addresses for stratix II.

Thanks a lot in advance!