debugging objects and some others about arrays

Hi all!
I'm working with the RFM22 library from Mike McCauley, the library works great but when I use it to build a datagram network it fails after some time, and I wrote some VB application to analize what is wrong with it.

Now when I dump the datagram object I fount a hex value like this: FFFFFF84
I mean i get the data byte per byte, like this:
0F 0A 01 FFFFFF84 00 02 0D ....

What can be this FFFFFF84 value? a mem pointer could be?

And other issue is about an array, is this valid ?

uint_8t my array [255];
mifunction (array,&lenarray); // this is a function that fills the arrays with 200 values and lenarray let me know with how many was filled

//and then i add more values to the arrar
myarray[lenarray] = 201;
myarray[lenarray+1] = 202;
myarray[lenarray+2] = 203;

lenarray = lenarray+3;

Is this code correct? it's working but is this codding the right way to add member to the array?

Best Regards!
Frank

What can be this FFFFFF84 value?

No, simply any byte value with sign-extension (0x84)

Can i leave this sign-extension value or is better try to found who produce it to set like an unsigned value?
It's my first time wih the sing-extension situation!

Best Regards
Frank

You could simply cast to a unsigned type.