Problems with send Nokia OL

[Alberto Starosta]

Hi.

I'm new here. This is my first mail.
I'm PHP programmer and I make application to send Nokia OL throught an 
italian gateway. Teoreticaly is very simple to send OL, but I have problems 
when I try to create my own logo (ex. LogoManager) and convert it in HEX, i 
have still problems to send it correctly:
example

OK:

$sms_text = 
"0000800000080003800000C00000180007E00000BFFFFFEFFFC3B00000808208083FE0100000413064101FF03000003E3067E01FDFE000000200021C3F8FC000000238E23C3E040000000247123E1E0E00000001B06C1F001E00000000B06B0F801E00000000800BC3878E000000007FF3E08F82000000002021C00F8400";

(this I found somewhere -> "cow" picture)

BAD:

$sms_text = 
"424DE6000000000000003E00000028000000480000000E0000000100010000000000000000000000000000000000020000000200000000000000FFFFFF00FF657B5377F7798003006E0017FDB5C3DABD58F281006F00C0B7AECFB0375BF78300760000001E0FE40257ED61006500F00DCF1AC942328DA3005000FF80173F96B0D61107006500FFFF8F2F1FD8F0787F000000FFFF6B7F2FD4713F7F000000FFFFF7347EF2F2EFFF006F00FFFFF3D81BDE7AFFFF006100FFFFABA38FF96DFFFF006F00FFFFFCCF43AFFCFFFF007600FFFF6A159A9DFDEBFF000B00FFFFFFBF3CEFF80FFF007500";

(this is my own picture)

Where is error ?

Thanks all. Please help me.