Failing to put together a mosaic in Star Alignment

[Tom OD]

Hi All,
I'm trying to use Star Alignment to make a large mosaic with about 20 panes. I can get about 6 so far to combine for a base layer. (I'm following the Creating a Seamless Supermosaic video on youtube)
For some panes however, the s/w isn't finding stars to match to continue to create the base layer. Some were taken with a mount flip, but even when I rotate the pic its taking 25 attempts to find matching stars. I abort the process at the stage. The panes that are giving me trouble do match, as I have done a small mosaic in PS and Registar.
Is this a common problem, and if so, does anyone have any tips to get a registered mosaic match with Star Alignment?
Thanks Tom.

[georg.viehoever]

See http://pixinsight.com/forum/index.php?topic=4903.msg33966#msg33966 , http://pixinsight.com/forum/index.php?topic=4910.msg34031#msg34031 , http://pixinsight.com/forum/index.php?topic=4868.msg33875#msg33875 . Try defining previews when doing the StarAlignment.

Georg

[Tom OD]

Thanks Georg,
I'll study these.
T.