Can't search USB external hardrive on 10.5.2

Earlier this week I had no problem searching an external UsB hardrive. It's got over 180GB of work on there and I really need to use the search facility. As of today (I recentley installed the 10.5.2 update) it won't find anything when I do a search. I type in the search field a name of a file/folder of something I can blatantly see I even type in the clients name which appears thousands of time and only one folder comes up. My Firewire Ext HD is fine and I can search that although it is OS X formatted while the other is PC formatted. I've tried searching both content and files and nothing comes up. Would anyone have any idea why this is? By the way I've put the Hard Drive on to someones elses mac who is running 10.4 and the search is fine.