Problem switching between sats

Hi
I have just set up a small system using a Triax 78 Dish with 3 Lnb's (13, 19 & 28 Deg)and a Diseqc switch with a DM500HD.When I start the receiver on Hotbird all is working fine, then move tp 19deg all is fine and then on to 28.2deg and all is fine. Now if I go back to 19 or 13 Deg I am not getting any signal. I have set up the tuner with the following settings:
Configuration Simple
Mode DIESqc A/B/C/D
Port A hOTBIRD
Port B Astra1
Port c Astra2
Port D nothing connected
Set Voltage and 22khz yes
Send DISEqc only on satellite change no

Advanced Hotbird Astra1 Astra 2
LNB. 1 2 3
Priority. Auto Auto Auto
LOF. uNIVERSAL lNB same same
Voltage mode. Polarization same same
Increased voltage. no same same
Tone mode. band same same
DISEqc mode. 1.0 same same
Toneburst . none same same
Committed DISEqc cpmmand. AA AB BA
fAST DIseQC. NO same same
Command order. committed toneburst same same

All help appreciated.
Thanks
Pedigree

Thanks Thijs
Yes all are Titanium 0.1db, using two single and one quad.
Pedigree

Hi All.
Can anyone help with this.
Thanks
Pedigree

To update:
I found the answer to this problem this summer, I statred to have poor reception on the weaker transponders on 28.2 deg, spent a lot of time checking allignment etc and came to the conclusion it was an Lnb problem. Changed the Lnb solved the signal problem and it also solved the switching problem. I don't know why but it did.
Pedigree