VSTi crashing Max

I've developed a simple patch using [vst~] which i've been loading VSTis into and controlling them with a comination of a MIDI keyboard and a P5 Glove, (with a bit of Max trickery to keep it interesting).

Most of my VSTis work fine but there's a few which cause Max to completely seize! Worse still when Max seizes up neither CTRL+Period or CTRL+ALT+DEL, (i'm on XP by the way), can close it and the only way to get out of it is a hard shutdown/power-down.

The two worst culprits are "Cygnus-O" and "Analog Warfare", (they're both superb and free, so well worth checking out!), and whilst they seem to top out at about 5%-6% CPU in Cubase....Max really doesn't seem to like them.

They've got around 100+ controller values each, so could that be why Max doesn't want to play or is it more likely to be a simple case of not enough processing power?

Some other VSTis struggle but don't cause a complete seizure, so my inclination is processing power although surely Max couldn't be that inefficient at running VSTs could it?

I'm running them on my new laptop, which isn't as powerfull as my desktop at home, so i'm wondering whether it's the laptop that's just not upto it or if incompatibility's the problem.

I'm away from home for a couple of weeks so i can't test them on my desktop until i get back, hence why i'm asking here without properly trouble shooting the problem first, but any advice or pointers would be appreciated.

Thanks in advance,
John