hmm, I don't know anything about guiminer, I use CGminer. You can get the gist of reflashing here
https://forum.litecoin.net/index.php/topic,2963.0.html I don't know what bios you would need. Before you flash things, is there a guide to setup guiminer somewhere? CGminer has the Scrypt-readme text file that comes with the program to get you started. It took me about 2 hours to dial the cards in to their max before flashing.
I tried cgminer directly as well using the following command but it produces same error (really pulling my hair lmao)
cgminer --scrypt -o
http://pool.litebonk.com:3333 -u username.1 -p passsword --thread-concurrency 8192 -I 10 -g 1 -w 256