Although my headers look slightly different to yours (no bi, bx, ds, etc) I found that a GET request does the trick. Here is my tamper data transcript:
1:24:34.883[278ms][total 278ms] Status: 302[Moved Temporarily]
POST http://www.abebooks.com/servlet/SearchResults Load Flags[LOAD_DOC
+UMENT_URI LOAD_INITIAL_DOCUMENT_URI ] Content Size[20] Mime Type[te
+xt/plain]
Request Headers:
Host[www.abebooks.com]
User-Agent[Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9) Gec
+ko/2008061017 Firefox/3.0]
Accept[text/html,application/xhtml+xml,application/xml;q=0.9,*/*
+;q=0.8]
Accept-Language[en-us,en;q=0.5]
Accept-Encoding[gzip,deflate]
Accept-Charset[ISO-8859-1,utf-8;q=0.7,*;q=0.7]
Keep-Alive[300]
Connection[keep-alive]
Referer[http://www.abebooks.com/]
Cookie[visited=false; H9U4=2-2-4AF2B353F25D1563A7EFF64C9C8C966F1
+CC47B51D9B4FC20BF7EC22C1159C36E-62EFF0DD7924B97457302616162F154647325
+FF38A3CBE949CD1AE8180BAE484; H9U4SE=1; abe_vc=1]
Post Data:
sts[t]
tn[Codex+Seraphinianus]
x[53]
y[15]
Response Headers:
Location[http://www.abebooks.com/servlet/SearchResults?sts=t&tn=
+Codex+Seraphinianus&x=53&y=15]
Content-Type[text/plain; charset=ISO-8859-1]
Content-Encoding[gzip]
Content-Length[20]
Expires[Thu, 17 Jul 2008 01:24:29 GMT]
Cache-Control[max-age=0, no-cache, no-store]
Pragma[no-cache]
Date[Thu, 17 Jul 2008 01:24:29 GMT]
Vary[Accept-Encoding]
Connection[keep-alive]
Notice the 302 response?
So I modified the url to look for some made up book title;
http://www.abebooks.com/servlet/SearchResults?sts=t&tn=Story+of+the+sea+urchin&x=53&y=15
And sent a GET request... voila!
Confucius says kill mosquito unless cannon