I've heard that other firmware versions are in beta test now. Hopefully there will be new release(s) soon that can address these issues.
Whatever is going wrong, the situation for some of us, at least, has been improving. I think that T-Mobile and Linksys are on the right track, as my own experience has been improving steadily since rollout of the service. So they've fixed the problems at least under *some* configurations.
There are apparently a number of variables, all tied up in the telecomm path between your phone, the router, your cable/DSL modem, T-Mobile's UMA network, and their backbone, that impact your experience. There could be quality of service tuning issues controlled by your ISP, the quality of the physical cabling connection between any of the components in this system (your router, house, ISP), bandwidth limitations, latency, packet size issues, etc. I'm guessing that there could be an enormous number of combinations of all of these factors that might contribute to a poor experience. As such, T-Mobile has to work with Linksys, get all of their own variables right -- and allow for the variable nature of all the factors that they cannot control, such your internal wiring, house-to-isp wiring, DSL/Cable modem firmware, QoS tuning at the head-end by your ISP, etc.
I get the impression that they're getting these factors under control, but it seems to be a pretty slow, gradual process.
The gradual improvement that I've experienced, though, encourages me. I think all this instability will be forgotten in the not too distant future, and we'll be able to think of this service pretty much the way we took POTS (plain old telephone service) for granted for the past 50 years.
