Slow responses from V boxes can be due to signal issues as well as box faults. As boxes are rented & hence fault callouts free it is worth getting checked out if symptoms persist for more than a week. Signal levels can usually be checked remotley by Customer Services.
Cable customer since 1993. Services: FH TV, Sky Sports & Movies (2xV6), Talk Anytime Phone, VIVID 350, Virgin PAYG Mobile
"Slow responses"... it froze for 20mins before I flipped the switch! Ran the usual "test your service" tests with a "no problems detected" response.
As I've got the VM guy coming on Monday anyway I'll continue to monitor and note down problems. So far I've had more problems with this VM box in 4 months than with EE's tv box when it was new and a bit buggy in 18months!