I waited until I got back to work to see if this was just a 32-bit issue, it appears to be happening in both 32-bit and 64-bit.
I have tested this file in Max9 32 & 64, Max 2010 32 & 64 with the same results.
The Plfow PRT Loader Update is not updating Position at rendertime when rendering the sequence. Single frames are fine, viewport update is fine, but render time is blank on first attempt and frame 0 for the duration on the second attempt.
I have attached an adjusted file (it is the same file from THIS thread but cleaned up)
It is, and the build is posted. Please download and test it.
We rolled 1.5.2 into 1.5.1 so it has lots of new goodies like Selection Channel, PRT Volume random and grid particles per voxel, Curve node in MagmaFlow and a sweet new Schematic Flow UI.