OK, the start of the file looks something like this (agreed?):
H Created on Sun, 14-Jan-2007 10:59:19 by TpSelect V2.1
H Format: Garmin PCX5AVD
H SOFTWARE NAME & VERSION
I PCX5 2.09
It's complaining about "no spaces after the record id" at line 3. This is true - there are no spaces after the 'H' in the third line.
Try editing the file to add a couple of spaces after the H in line 3 (in Notepad or something). If that fixes the problem, please let me know and I will fix the program to do just that.
Seems that your version of Mapsource is being very fussy