Prova a usare/semplificare/completare questa:

codice:
rv = false;
spiders = Split("Spider,ArchitextSpider,MaxBot.com,allothers,ESISmartSpider,FAST-WebCrawler,xcrawler,AllOthers,GreatWhiteCrawl,altavista,Scooter,G.R.A.B.,scooter,Mercator,crawler,inktomi,Slurp,Googlebot,google,Gulliver,NorthernLight,lycosidae,lycos,Lycos_Spider,T-Rex,InfoSeek,infoseek,ArchitextSpider,excite,InnerpriseBot,Faxobot,TurnitinBot,LinkWalker", ",")
for kk = Lbound(spiders) to Ubound(spiders)
	if inStr(Request.ServerVariables("HTTP_USER_AGENT"),spiders(kk))>0 then rv = true
next
ciao