here's a strange problem where valid channels (ie included in subscription package) sometimes incorrectly show as blank lines when scrolling up/down in the HD Guide.
it seems that this is related to preview channels, ie. a different artifact of the problem I reported previously where preview channels don't disappear from the guide when the free period is over. But additionally in this case, scrolling the guide results in channels names/icons on the left getting temporarily unsynchronized with the associated program data in the grid to the right.
here's a specific example. I subscribe to Personal TV + Best of HD, which includes channels 147 TSN2 and channel 157 Big Ten Sports in the package. I notice that there was a free preview of Salt+Light TV ch160 and also Investigation Discovery ch172 - I believe the free preview of one or both of them might have just ended
here is a sequence of screenshots showing the problem, each taken a few seconds apart:
1. first screen shows ch147 and ch157 in the guide view, appearing normally
2. now press page down button - the guide did NOT scroll down - ch147 incorrectly still appears at top of list, but now is blank, along with ch157
Notice also that the program listings on the right did change but do NOT match the channels indicated on the left (compare to step 1)
3. press page down button again, the guide listing seems to advance beyond the expected next page, now ch229 is top of the list
4. press page up button, the guide listing now shows the previous "missed" page, but note that ch160 and ch172 are blank (1st and 4th lines - these are same lines as incorrect blank lines in step 2). Also notice that the shown channel listings are the same programs show in step 2.
5. press page up button, now ch147 and ch157 display correctly again.
if you repeat scrolling down/up through the guide, the same thing happens
The conclusion is that in step 2, the guide data grid to the right advanced, but the channel listing on the left did not, so it seems this incorrect grid screen is related to the preview channels that are finally revealed in step 4.
I have seen this kind of strange behaviour in the guide before, where scrolling down the guide doesn't always advance the listings and causes mis-matched channels on the left vs data on the right - but this is the first time I've noticed that it somehow involved preview channels. I'm guessing once these free preview channels properly disappear from the guide, this strange behaviour of the other valid channels will go away - but as I've noted before, it seems to take several weeks for preview channels to disappear after they're no longer authorized.