indeed. it's a duemilanove board though the chip now has optiboot installed. but yeah, getting the environment setup on gentoo was rather tricky, so i'm being pushed that way more and more. having tried a completely different bootloader several times, that definitely can't be the issue.
the sketch that i posted was complete. simple including the SD.h library cause the sketch to crash. user deif posted a stripped down sd_raw library to the forum (Arduino Forum) which contains a commented sd_raw_get_info() function. with that function commented, the sketch uploads and runs and actually prints an error (since i have no pins connected to the board yet). if i uncomment the function, the size goes to 4.6+k and crashes. i get no errors and it uploads fine. i've recompiled avrdude, upgraded the IDE, and now i'm left with avr-gcc and the system setup. i figured the strangeness was worthy of a forum post. thanks for you input!