I use MystMoods with no problem here.
If you look in the lensflares folder, that's where you will find lens_14.tga
Maybe it got corrupted somehow.

Windows XP SP3
Intel Dual Core CPU: E5200 @ 2.5GHz
4.00GB DDR3 Ram
ASUS P5G41T-M LX
PCIE x16 GeForce GTS 450 1Gb
SB Audigy 4
Spyware Doctor with AntiVirus