Flak proj effects not moving bug

This is an odd bug that has been testing my patience. What happens is that the projectile effects for the flak guns I’ve added (essentially missiles with no tracking and a high explosive radius) just sit still in space where they were fired. This screen shot was taken two seconds after the guns were fired:

The effects were working fine until I installed the 1.1 patch for Freelancer, and reverting to 1.0 solves the problem again. I am not using a modified exe. Common.dll, Server.dll, and Content.dll are modified; however, replacing these with the unmodified does not solve the problem.

Some notes:

• This is a visual bug only, the weapons can still hit targets and deal damage.

• Other missiles show no signs of this problem.

• The projectile effecst will very rarely fly outwards as they are supposed to. This most often happens immediately after taking a screen shot.

• Increasing the acceleration applied by the motor results in the effect accelerating, but only directly forwards from the ship that fired the weapon and not in the direction the weapon was fired.

• Changing the constant_effect results in no change.

For reference here is the code for the flak weapons.

[Motor]
nickname = prototype_flak_5tur_motor
lifetime = 1.000000
accel = 1.000000
delay = 0

[Explosion]
nickname = prototype_flak_5tur_explosion
effect = ku_missile01_impact
lifetime = 0.000000, 0.000000
process = disappear
strength = 100
radius = 100
hull_damage = 22.2222
energy_damage = 0
impulse = 0.000000

[Munition]
nickname = prototype_flak_5tur_ammo
explosion_arch = prototype_flak_5tur_explosion
loot_appearance = ammo_crate
units_per_container = 10000
hp_type = hp_gun
requires_ammo = true
hit_pts = 2
one_shot_sound = fire_bolt_long
detonation_dist = 60
lifetime = 3.000000
Motor = prototype_flak_5tur_motor
force_gun_ori = false
const_effect = br_flakcannon01_proj
HP_trail_parent = HPExhaust
seeker = dumb
time_to_lock = 0
seeker_range = 2100
seeker_fov_deg = 0
max_angular_velocity = 0
ids_name = 550033
ids_info = 550033
mass = 0.000000
volume = 0.000404

[Gun]
nickname = prototype_flakcannon_5tur
ids_name = 550032
ids_info = 550032
DA_archetype = equipment\models\weapons\li_smlturret.cmp
material_library = equipment\models\li_equip.mat
HP_child = HPConnect
hit_pts = 5000
explosion_resistance = 0.800000
debris_type = debris_normal
parent_impulse = 20
child_impulse = 80
volume = 3.000000
mass = 3
hp_gun_type = hp_turret_special_1
damage_per_fire = 0
power_usage = 0.000000
refire_delay = 0.444444
muzzle_velocity = 399.000000
dispersion_angle = 1.333333
toughness = 2.400000
flash_particle_name = li_laser_03_flash
flash_radius = 15
light_anim = l_gun01_flash
projectile_archetype = prototype_flak_5tur_ammo
dry_fire_sound = fire_dry
separation_explosion = sever_debris
auto_turret = true
turn_rate = 90
lootable = true
LODranges = 0, 20, 60, 2000

[Gun]
nickname = prototype_flakcoil_5tur
ids_name = 550034
ids_info = 550034
DA_archetype = equipment\models\weapons\li_smlturret5.cmp
material_library = equipment\models\li_equip.mat
HP_child = HPConnect
hit_pts = 5000
explosion_resistance = 0.800000
debris_type = debris_normal
parent_impulse = 20
child_impulse = 80
volume = 3.000000
mass = 3
hp_gun_type = hp_turret_special_1
damage_per_fire = 0
power_usage = 0.000000
refire_delay = 0.444444
muzzle_velocity = 699.000000
dispersion_angle = 1.333333
toughness = 2.400000
flash_particle_name = li_laser_03_flash
flash_radius = 15
light_anim = l_gun01_flash
projectile_archetype = prototype_flak_5tur_ammo
dry_fire_sound = fire_dry
separation_explosion = sever_debris
auto_turret = true
turn_rate = 90
lootable = true
LODranges = 0, 20, 60, 2000

Well fiddling with the motor values works. I still don’t know exactly how though as increasing the engine life to 3 or acceleration to 100 both worked, but increasing the acceleration to 400 and reducing life to 0.25 didn’t.

At least I know what to fiddle with to make it work. Thanks for the help.