My host has recently upgraded PHP from 4.4.8 to 5.2.5 as the default.

Normally I receive upwards of 20,000 entries per day.

With PHP 4.4.8 I have no problems at all in displaying this quantity

With PHP 5.2.5 I can display fine up to 1,500 to 2,000 entries
Any more than this and I receive a "blank page"

I am using zen-cart 1.3.8a
MySQL 5.0.67-community-log
Apache/2.2.9

At this time I can switch between PHP versions but my host will soon remove 4.4.8

Any ideas what might be causing this problem?