Advice for a PS/2 to USB splitter device

Hello to all

I posted this on the comp.sys.ibm.pc.hardware.misc newsgroup, and the
answers are basically - Your Mileage May Vary (YMMV) - so try it out.
In terms of time and energy, this is not a good route. Then again, I'm
sure someone in this newsgroup has done some USB work and maybe you can
share your valuable experience here.

Thank you in advance.

Situation
---------
With new laptops sporting only USB ports, I hooked up my PS/2 ergonomic
mouse and keypad to a single USB port via one those el cheapo splitters
(costs about US$7) to my ThinkPad R51.

Every now and then, the mouse and keypad will hang, so I have to unplug
and plug the device to reset it. Very troublesome of course. The shop
says I should buy ths US$30 version - but no guarantees and no $ back! I
can try it in the shop, though.

I would appreciate it if anyone has some advice on a good brand to buy,
the caveats in buying, etc etc.

Thank you in advance