Hello, some days ago notice that my N900 shows the sd card as corrupted, the sd card was working perfect the day before, I check the card in my laptop and to my surprice the sd works perfect, I all ready try formatting the card in the laptop but the n900 still shows the sd card as corrupted or bad format. I try a brand new sd card but my N900 shows the same problem.

This is a paste of my dmesg after running format sd card on my N900

[20977.524963] cam_shutter (GPIO 110) is now closed
[21089.947387] mmcblk0: retrying using single block read
[21089.951812] mmcblk0: error -84 transferring data, sector 0, nr 8, card status 0x900
[21089.951843] end_request: I/O error, dev mmcblk0, sector 0
[21089.961791] mmcblk0: error -84 transferring data, sector 1, nr 7, card status 0x900
[21089.961822] end_request: I/O error, dev mmcblk0, sector 1
[21089.968750] __ratelimit: 15 callbacks suppressed
[21089.968780] Spurious DMA IRQ
[21089.969116] mmcblk0: error -84 transferring data, sector 2, nr 6, card status 0x900
[21089.969146] end_request: I/O error, dev mmcblk0, sector 2
[21089.971832] mmcblk0: error -84 transferring data, sector 3, nr 5, card status 0x900
[21089.971862] end_request: I/O error, dev mmcblk0, sector 3
[21089.981781] mmcblk0: error -84 transferring data, sector 4, nr 4, card status 0x900
[21089.981811] end_request: I/O error, dev mmcblk0, sector 4
[21089.991790] mmcblk0: error -84 transferring data, sector 5, nr 3, card status 0x900
[21089.991821] end_request: I/O error, dev mmcblk0, sector 5
[21090.001800] mmcblk0: error -84 transferring data, sector 6, nr 2, card status 0x900
[21090.001800] end_request: I/O error, dev mmcblk0, sector 6
[21090.011779] mmcblk0: error -84 transferring data, sector 7, nr 1, card status 0x900
[21090.011810] end_request: I/O error, dev mmcblk0, sector 7
[21090.026214] mmcblk0:<4>mmcblk0: retrying using single block read
[21090.031951] mmcblk0: error -84 transferring data, sector 0, nr 8, card status 0x900
[21090.031951] end_request: I/O error, dev mmcblk0, sector 0
[21090.032562] Spurious DMA IRQ
[21090.032714] mmcblk0: error -84 transferring data, sector 1, nr 7, card status 0x900
[21090.032745] end_request: I/O error, dev mmcblk0, sector 1
[21090.040374] Spurious DMA IRQ
[21090.040466] mmcblk0: error -84 transferring data, sector 2, nr 6, card status 0x900
[21090.040466] end_request: I/O error, dev mmcblk0, sector 2
[21090.041809] mmcblk0: error -84 transferring data, sector 3, nr 5, card status 0x900
[21090.041839] end_request: I/O error, dev mmcblk0, sector 3
[21090.048187] Spurious DMA IRQ
[21090.048492] mmcblk0: error -84 transferring data, sector 4, nr 4, card status 0x900
[21090.048522] end_request: I/O error, dev mmcblk0, sector 4
[21090.051818] mmcblk0: error -84 transferring data, sector 5, nr 3, card status 0x900
[21090.051849] end_request: I/O error, dev mmcblk0, sector 5
[21090.055999] Spurious DMA IRQ
[21090.056091] mmcblk0: error -84 transferring data, sector 6, nr 2, card status 0x900
[21090.056121] end_request: I/O error, dev mmcblk0, sector 6
[21090.061798] mmcblk0: error -84 transferring data, sector 7, nr 1, card status 0x900
[21090.061798] end_request: I/O error, dev mmcblk0, sector 7
[21090.061828] Buffer I/O error on device mmcblk0, logical block 0
[21090.062530] mmcblk0: retrying using single block read
[21090.063812] Spurious DMA IRQ
[21090.063995] mmcblk0: error -84 transferring data, sector 0, nr 8, card status 0x900
[21090.064025] end_request: I/O error, dev mmcblk0, sector 0

Any help is really apresiated

Thank you

Sorry to say this but I had more or less the same problem. Even after a reflash of image and Emmc.
Had to send it back to Nokia who thankfully sent a replacement.
Try flashing first if not send it back to Nokia.

Try downloading h2test and testing the card inside and outside of the N900. When I had a problem like this it was the card not the handset.