Hrm, I'm currently learning Pali, which is similar to Sanskrit in some respects, so good luck. I managed to dig this up for you, not sure if it's in the above torrent or not:
Thomas Egenes Introduction to Sanskrit, Parts 1 and 2
http://www.megaupload.com/?d=POAZTJRF
http://www.megaupload.com/?d=WA460846
I tried to dig up some links to 'Teach Yourself Sanskrit,' but it appears the files have all been removed. You could try asking the guy on Demonoid who put up the 'Teach Yourself' gigatorrent(which has alot of other great 'Teach Yourself' language books in it btw.) In the description he says the only reason he hasn't uploaded the Sanskrit book is because he lacks the audio, the thing is, I don't think Teach Yourself Sanskrit ever had audio... :P
Also, Google Books has a lot of old Sanskrit Grammars, you might try hitting that up.
Anyway, enjoy.