Perhaps, I was little over but I thought you are not giving credence to Rig Ved.
Rig ved mein eak shlok hai use dekhiye ki kahin aapko haravati ya uske aas paas ka kuch samaj mein aata hai:
ऋिग वेद २.२६.६
त्वं नो गोपा: पथिकृद्विचक्षणस्तव व्रताय मतिभिर्जरामहे ।
हस्पते यो नो अभि ह्वरो दधे स्वा तं मर्मर्तु दुच्छुना
हरस्वती ॥
(last line - हमारे प्रति जो भी कुटिलता का व्यवहार करे, उसे उसकि ही दुर्बुद्धि नष्ट कर दे ।)
You, Br.haspati, are our protector and the guide of (our) path; (you are) the discerner (of all things); we worship with praises for your adoration; may his own precipitate malice involve him (in destruction)
who practises deceit against us.
Reference in Rig-Ved to Harasvati, not contextually to any river whatsoever. Its meaning refers to deceive or kutiltah.
Aur usi mandal mein Saraswati naam ki nadi ka varnan.
ऋिग वेद २.४१.१६
अम्बितमे नदितमे देवितमे सरस्वति ।
अप्रशस्ता इव स्मसि प्रशस्तिमम्ब नसक्रधि ॥
(हे नदियों, मातृगणों, देवों मे सर्वश्रेषठ सरस्वति or Best Mother, best of Rivers, best of Goddesses, Sarasvati)
aur yeh Saraswati kahan thi, yamuna aur Satlej (Sutudri) ke beech:
इमं मे गग़ें यमुने सरस्वति सुतुद्रि स्तोम् सचता परुष्ण्या ।
असिक्न्या मरुवृद्धे वितस्तयार्जीकीये श्रृणुह्या सुषोमया ॥
Above 2 examples are for all those who always refer Saraswati to symbolism and Harasvati as a real river after which Sarasvati was named. Rig-Ved offers exactly the opposite. Saraswati is a river and Harasvati is symbolism (deceit or malice), not a river.
In addition, producing something from Ishwa on this debate (thanks to Ravi for pointing this out, who actually started a mini debate on this many years ago):
While we see that Saraswati finds mention in RV (above) as a river, it corresponding Haraswati is not referred to as river. So the natural question is when does Harasvati find mention as a river and where does this occur? It does occur, once again in later Vedic text. Harasvatya is also mentioned as a great motherly river (name) in the Atharvaveda Parishish.t.a, along with generic names for rivers, in this series: .....sindhavah, kulyâh, vahâh, urvyah, irâvatyah, pârvatyah, ojasvatyah, sarasvatyah, harasvatyah, ajirâh mâtarah nadînÃm. (AVParish. 48 Kautsavya Niruktanighan.tuh)
It seems that the word Harasvatî and its derivative Harasvatya is not identical with the word Sarasvatî in meaning, (or perhaps eventually not with that river?).
In addition, I would like to point to what Ravi just put on Jat History about this topic:
http://groups.yahoo.com/group/JatHistory/message/7653