I have had similar issues occur with an external hard-drive plugged into an AEBS (then the inevitable sparse bundle problem when connecting directly to my macbook! grrr).
However before blaming the TC, maybe check your wireless card (does it fault at all - check logs), the type of wireless connection (if using n, note that there might be different implementations of it on the pc vs TC), also how is the share set up, if set up to use samba, check the version the TC uses (as it has a preference for AFP. Next check the signal strength, and whether you are trying to send files when your pc isn't plugged in (if a laptop), as often your wireless card will dial back the power to save battery, and signal interference becomes a problem.
Lastly there is an option when setting up wireless connections to use interference robustness, and also check the channel you are using for the wireless for interference from others.