That is the first report I heard of having corruption issue with either the SDHC patch (earlier firmware) or the MMC Plus patch (current firmware). Personally I have had no issues with my 8GB Patriot SDHC card with either of the patches. In addition the (now fried, due to testing in another N800 with stock Nokia kernel!) 4GB non-SDHC card worked fine with with patched kernels.