Caching in the views is off. Does not seem like caching issue. Hook_preprocess_views_view is not called when next set of rows are being called via Ajax pager? Is there any way to preprocess variable array rows coming from AJAX?

@Clive This page-> admin/reports/dblog shows no error logs related to maximum execution time. The only log which i see is- SPI update server response messages: SPI data processing has been queued. Not sure what does this mean.

Is there any other way to make this work without changing the maximum execution time on server.

Did u get the answer to this question? because I am also in the same situation and need answer for this.

no. I am migrating both from drupal5 site