Hm. X2 does take a long time the first time that you open the style manager – as it was explained to me, it tends to front-load a lot of the data which makes for longer load times initially, but faster performance later on – but a long wait when inserting a reference is typically indicative of some kind of trouble accessing / editing the system registry. Typically we see that happen once right after resetting preferences or (re)installing the program, and then it doesn’t happen again. Were you running Vista, I’d blame UAC, but in XP it’s usually due to some kind of third-party registry protector or antivirus or antispyware program.