[old_tv_nut]

Just checked with a colleague of mine who worked on the captioning capability of VHS, who says:

"...normal VHS machines will not record teletext. The data rate is too high. Captioning is a lower rate and gets through.
On S-VHS machines the recording has a wider bandwidth and can record the teletext signal. However there is a comb filter that separates the color from lumance. This destroys the data and needs to be turned off during the teletext interval."