Did you look at rows 11184/11185? Is it possible that the data on these rows might be incomplete or not able to be parsed with either of the format specifiers that you used?
When I run the code I get an error "??? Error using ==> textscan Param/value pairs must come in pairs." This seems to come from the inf value which is entered as one of the textscan options. Removing this inf gives me a 1x2 cell... but with empty cells, due to not having header lines :)
I made some small changes to the code you supplied (particularly the string format), and this imports the data correctly:
filename = 'temp.txt';
fid = fopen(filename,'r');
formatspec = ['%q',repmat('%f',1,28)];
A = textscan(fid, formatspec, 'Delimiter',',', 'CollectOutput', true);
fclose(fid);
It is likely to be something specific to the rows where these formats do not parse the data...
Note that using importdata also works for me:
B = importdata(filename, ',');
