I use a UPS too, mainly for surge protection of delicate and expensive electronics. I do think that Alge have done some significant work on the Timy driver to deal with these problems. The number of posts in this thread has dropped off a lot, so either everyone switched to serial connection or the failures aren't happening nearly as much. Nonetheless I still need to run the Com To File utility for my laptops to see Timy with the new driver installed.
I've been running an extra Timy via USB this winter just to see if it will fail; you could call it the B' timer. Timing signals come via blinky box and the computer is one of the 'race use only' machines so there is no background junkware clogging up the works. So far through two weekends of SL it's 100.00% successful, same as the other two timer/laptop pairs (with serial connections). But then we had no problems in the past to speak of either. I do think it was software issues that were taking down USB connection in the past, mostly due to 'dirty' computers.