Putting values in dynamic array of strings

[Heavy Metal]

I have declared a dynamic array of strings as thus:

char **testfile;

testfile = malloc(sizeof(char *) * 50);

for(j=0;j<count;j++)
{
testfile[j] = malloc(count * sizeof(char));
}

I am reading strings from a file into the array like this:

j=0;
while(fgets(testfile[j], 80, fp) != NULL)
{
j++;
}

But when I deallocate the dynamic memory like this:

for(j=0;j<count;j++)
{
free(testfile[j]);
counter++;
}
free(testfile);

I get an error message:

Debug Error!

Damage: after Normal Block(#42) at 0x00300180

The thing which is confusing me, if i don't fill the array with values, basically commenting out the lines of code which fill the array, I don't get the error message when I deallocate the memory.

I would truly appreciate any words of wisdom regarding my problem.

Thank you,
TJ